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Sample records for active auroral research

  1. Upper atmospheric effects of the hf active auroral research program ionospheric research instrument (HAARP IRI)

    SciTech Connect

    Eccles, V.; Armstrong, R.

    1993-05-01

    The earth's ozone layer occurs in the stratosphere, primarily between 10 and 30 miles altitude. The amount of ozone, O3, present is the result of a balance between production and destruction processes. Experiments have shown that natural processes such as auroras create molecules that destroy O. One family of such molecules is called odd nitrogen of which nitric oxide (NO) is an example. Because the HAARP (HF Active Auroral Research Program) facility is designed to mimic and investigate certain natural processes, a study of possible effects of HAARP on the ozone layer was conducted. The study used a detailed model of the thermal and chemical effects of the high power HF beam, which interacts with free electrons in the upper atmosphere above 50 miles altitude. It was found only a small fraction of the beam energy goes into the production of odd nitrogen molecules, whereas odd nitrogen is efficiently produced by auroras. Since the total energy emitted by HAARP in the year is some 200,000 times less than the energy deposited in the upper atmosphere by auroras, the study demonstrates that HAARP HF beam experiments will cause no measurable depletion of the earth's ozone layer.... Ozone, Ozone depletion, Ozone layer, Odd nitrogen, Nitric oxide, HAARP Emitter characteristics.

  2. Mapping auroral activity with Twitter

    NASA Astrophysics Data System (ADS)

    Case, N. A.; MacDonald, E. A.; Heavner, M.; Tapia, A. H.; Lalone, N.

    2015-05-01

    Twitter is a popular, publicly accessible, social media service that has proven useful in mapping large-scale events in real time. In this study, for the first time, the use of Twitter as a measure of auroral activity is investigated. Peaks in the number of aurora-related tweets are found to frequently coincide with geomagnetic disturbances (detection rate of 91%). Additionally, the number of daily aurora-related tweets is found to strongly correlate with several auroral strength proxies (ravg≈0.7). An examination is made of the bias for location and time of day within Twitter data, and a first-order correction of these effects is presented. Overall, the results suggest that Twitter can provide both specific details about an individual aurora and accurate real-time indication of when, and even from where, an aurora is visible.

  3. Measurements of thermospheric response to auroral activities

    NASA Technical Reports Server (NTRS)

    Okano, S.; Kim, J. S.

    1986-01-01

    The Joule heating produced by auroral electrojets and its thermospheric response can be studied by monitoring the thermospheric temperatures by optical methods; simultaneously, the concurrent auroral electrojet activities can be investigated by using geomagnetic records obtained from stations along a meridian close to the observation site of optical measurements. The measurements are reported of thermospheric response to auroral activities which were made at Albany (42.68 deg N, 73.82 deg W), New York on September 2, 1978 (UT) when an isolated substorm occured. The thermospheric temperatures were measured by using a high resolution Fabry-Perot interferometer that determines the line profiles of the (OI) 6300A line emission. The intensities and latitudinal positions of auroral electrojets were obtained by the analysis of magnetograms from the IMS Fort Churchill meridian chain stations.

  4. Temporal evolution of pump beam self-focusing at the High-Frequency Active Auroral Research Program

    NASA Astrophysics Data System (ADS)

    Kosch, M. J.; Pedersen, T.; Mishin, E.; Starks, M.; Gerken-Kendall, E.; Sentman, D.; Oyama, S.; Watkins, B.

    2007-08-01

    On 4 February 2005 the High-Frequency Active Auroral Research Program (HAARP) facility was operated at 2.85 MHz to produce artificial optical emissions in the ionosphere while passing through the second electron gyroharmonic. All-sky optical recordings were performed with 15 s integration, alternating between 557.7 and 630 nm. We report the first optical observations showing the temporal evolution of large-scale pump wave self-focusing in the magnetic zenith, observed in the 557.7 nm images. These clearly show that the maximum intensity was not reached after 15 s of pumping, which is unexpected since the emission delay time is <1 s, and that the optical signature had intensified in a much smaller region within the beam after 45 s of pumping. In addition, adjacent regions within the beam lost intensity. Radar measurements indicate a plasma depletion of ~1% near the HF reflection altitude. Ray tracing of the pump wave through the plasma depletion region, which forms a concave reflecting radio wave mirror, reproduces the optical spatial morphology. A radio wave flux density gain of up to ~30 dB may occur. In addition, the ray trace is consistent with the observed artificial optical emissions for critical plasma frequencies down to ~0.5 MHz below the pump frequency.

  5. Do interplanetary Alfven waves cause auroral activity?

    NASA Technical Reports Server (NTRS)

    Roberts, D. Aaron; Goldstein, Melvyn L.

    1990-01-01

    A recent theory holds that high-intensity, long-duration, continuous auroral activity (HILDCAA) is caused by interplanetary Alfven waves propagating outward from the sun. A survey of Alfvenic intervals in over a year of ISEE 3 data shows that while Alfvenic intervals often accompany HILDCAAs, the reverse is often not true. There are many Alfvenic intervals during which auroral activity (measured by high values of the AE index) is very low, as well as times of high auroral activity that are not highly Alfvenic. This analysis supports the common conclusion that large AE values are associated with a southward interplanetary field of sufficient strength and duration. This field configuration is independent of the presence of Alfven waves (whether solar generated or not) and is expected to occur at random intervals in the large-amplitude stochastic fluctuations in the solar wind.

  6. Sophus Peter Tromholt: an outstanding pioneer in auroral research

    NASA Astrophysics Data System (ADS)

    Moss, K.; Stauning, P.

    2012-03-01

    The Danish school teacher Sophus Peter Tromholt (1851-1896) was self-taught in physics, astronomy, and auroral sciences. Still, he was one of the brightest auroral researchers of the 19th century. He was the first scientist ever to organize and analyse correlated auroral observations over a wide area (entire Scandinavia) moving away from incomplete localized observations. Tromholt documented the relation between auroras and sunspots and demonstrated the daily, seasonal and solar cycle-related variations in high-latitude auroral occurrence frequencies. Thus, Tromholt was the first ever to deduce from auroral observations the variations associated with what is now known as the auroral oval termed so by Khorosheva (1962) and Feldstein (1963) more than 80 yr later. He made reliable and accurate estimates of the heights of auroras several decades before this important issue was finally settled through Størmer's brilliant photographic technique. In addition to his three major scientific works (Tromholt, 1880a, 1882a, and 1885a), he wrote numerous short science notes and made huge efforts to collect historical auroral observations (Tromholt, 1898). Furthermore, Tromholt wrote a large number of popular science articles in newspapers and journals and made lecture tours all over Scandinavia and Germany, contributing to enhance the public educational level and awareness. He devoted most of his life to auroral research but as a self-taught scientist, he received little acclaim within the contemporary academic scientific society. With his non-academic background, trained at a college of education - not a university - he was never offered a position at a university or a research institution. However, Sophus Tromholt was an outstanding pioneer in auroral research.

  7. A study of auroral activity in the nightside polar cap

    SciTech Connect

    Wu, Q.

    1989-01-01

    Using various ground observations at South Pole, Antarctica (invariant magnetic latitude -74{degree}) and its conjugate point, Frobisher Bay, Canada, the author has studied the following aspects of nightside polar cap auroral activity: the appearance and disappearance of polar cap auroras (diffuse and discrete) associated with substorms and interplanetary magnetic field (IMF) variations; auroral optical emission line intensities; and the seasonal variation of auroral conjugacy. The observations show that the polar cap auroras usually fade away before the expansive phase of a substorm and bright auroral arcs reach high latitude (-74{degree}) near the recovery phase. Just before the auroras fade away the discrete polar cap auroral arcs, which are usually on the poleward boundary of the diffuse aurora, intensify for 1 to 2 minutes. The observations also indicate the IMF may have stronger control over polar cap auroral activity than do substorms. A search for energy spectral variation of precipitating electrons using the intensities of 630.0 nm (0) and 427 nm (N{sub 2}{sup +}) auroral emission lines reveals no dramatic changes in the energy spectrum; instead, the data show possible atmospheric scattering and geometric effects on the photometric measurements while the bright auroral arc is moving into the polar cap. The conjugate observations show that the stormtime auroral electrojet current, which is associated with the bright auroral arc, in most cases reaches higher (lower) latitudes in the winter (summer) hemisphere. An asymmetric plasma sheet (with respect to the neutral sheet) is proposed, which expands deeper into the winter lobe, under a tilted geomagnetic dipole. Accordingly, the winter polar cap would have smaller area and the auroral electrojet would be at higher latitude.

  8. Dayside Auroral Activity During Solar Maximum and Minimum Periods

    NASA Astrophysics Data System (ADS)

    Rawie, M.; Fasel, G. J.; Flicker, J.; Angelo, A.; Bender, S.; Alyami, M.; Sibeck, D. G.; Sigernes, F.; Lorentzen, D. A.; Green, D.

    2014-12-01

    It is well documented that the dayside auroral oval shifts equatorward when the interplanetary magnetic field (IMF) Bz-component turns southward [Burch, 1973; Akasofu, 1977; Horwitz and Akasofu, 1977; Sandholt et al., 1986, 1988]. During these periods of oval expansion dayside transients are observed to move away from the poleward edge of the auroral oval and drift poleward. These poleward-moving auroral forms are believed to be ionospheric signatures of dayside merging. The dayside auroral oval usually begins to contract when the interplanetary magnetic field turns sharply northward, Bz>0. Eighteen years of meridian scanning photometer (MSP) data from the Kjell Henriksen Observatory in Longyearbyen, Norway are analyzed. During the boreal winter the Sun is several degrees below the horizon. This permits optical observations throughout the daytime period. The MSP Data is selected two hours before and after local noon in Longyearbeyn. Solar wind data (solar wind pressure and speed, along with the IMF Bx, By, Bz components) are collected for each interval and combined with the MSP observations. This data is then separated using solar maximum and minimum periods. Auroral activity (oval expansions and contractions along with the frequency and number of poleward-moving auroral forms) is documented for both solar maximum and minimum periods.

  9. Electromagnetic interference impact of the proposed emitters for the High Frequency Active Auroral Research Program (HAARP). Interim report

    SciTech Connect

    Robertshaw, G.A.; Snyder, A.L.; Weiner, M.M.

    1993-05-14

    The proposed HAARP emitters at the Gakona (Alaska) preferred site and at the Clear AFS (Alaska) alternative site are the Ionospheric Research Instrument (IRI), the Incoherent Scatter Radar (ISR), and the Vertical Incidence Sounder(VIS). The electromagnetic interference (EMI) impact of those emitters on receiving systems in the vicinity of the sites is estimated in this study. The results are intended for use as an input to the Air Force Environmental Impact Statement as part of the Environmental Impact Analysis Process.

  10. Approximating ambient D-region electron densities using dual-beam HF heating experiments at the high-frequency Active Auroral Research Program (HAARP)

    NASA Astrophysics Data System (ADS)

    Agrawal, Divya

    Dual-beam ELF/VLF wave generation experiments performed at the High-frequency Active Auroral Research Program (HAARP) HF transmitter in Gakona, Alaska are critically compared with the predictions of a newly developed ionospheric high frequency (HF) heating model that accounts for the simultaneous propagation and absorption of multiple HF beams. The dual-beam HF heating experiments presented herein consist of two HF beams transmitting simultaneously: one amplitude modulated (AM) HF beam modulates the conductivity of the lower ionosphere in the extremely low frequency (ELF, 30 Hz to 3 kHz) and/or very low frequency (VLF, 3 kHz to 30 kHz) band while a second HF beam broadcasts a continuous waveform (CW) signal, modifying the efficiency of ELF/VLF conductivity modulation and thereby the efficiency of ELF/VLF wave generation. Ground-based experimental observations are used together with the predictions of the theoretical model to identify the property of the received ELF/VLF wave that is most sensitive to the effects of multi-beam HF heating, and that property is determined to be the ELF/VLF signal magnitude. The dependence of the generated ELF/VLF wave magnitude on several HF transmission parameters (HF power, HF frequency, and modulation waveform) is then experimentally measured and analyzed within the context of the multi-beam HF heating model. For all cases studied, the received ELF/VLF wave magnitude as a function of transmission parameter is analyzed to identify the dependence on the ambient D-region electron density (Ne) and/or electron temperature ( Te), in turn identifying the HF transmission parameters that provide significant independent information regarding the ambient conditions of the D-region ionosphere. A theoretical analysis is performed to determine the conditions under which the effects of Ne and Te can be decoupled, and the results of this analysis are applied to identify an electron density profile that can reproduce the unusually high level of ELF

  11. Joseph Henry and John Henry Lefroy A common 19th century vision of auroral research

    NASA Astrophysics Data System (ADS)

    Silverman, S. M.

    Research on solar-terrestrial relationships today relies primarily on in situ space data. These data, however, cover only a short period of about 30 years. Many solar and related phenomena vary on much longer time scales. For the study of these, parameters such as sunspots, magnetic activity, auroral occurrence, or other proxy data are required. Historical records of aurora are particularly useful in this connection.

  12. Energy Characteristics of Auroral Electron Precipitation: A Comparison of Substorms and Pressure Pulse Related Auroral Activity

    NASA Technical Reports Server (NTRS)

    Chua, D.; Parks, G. K.; Brittnacher, M. J.; Peria, W.; Germany, G. A.; Spann, J. F., Jr.; Carlson, C.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    The Polar Ultraviolet Imager (UVI) observes auroral responses to incident solar wind pressure pulses and interplanetary shocks such as those associated with coronal mass ejections. The arrival of a CME pressure pulse at the front of the magnetosphere results in highly disturbed geomagnetic conditions and a substantial increase in both dayside and nightside auroral precipitation. Our observations show a simultaneous brightening over broad areas of the dayside and nightside aurora in response to a pressure pulse, indicating that more magnetospheric regions participate as sources for auroral precipitation than during isolated substorms. We estimate the average energies of incident auroral electrons using Polar UVI images and compare the precipitation energies during pressure pulse associated events to those during isolated auroral substorms. Electron precipitation during substorms has average energies greater than 10 keV and is structured both in local time and magnetic latitude. For auroral intensifications following the arrival of a pressure pulse or interplanetary shock, electron precipitation is less spatially structured and has greater ux of lower energy electrons (Eave _ 7 keV) than during isolated substorm, onsets. The average energies of the precipitating electrons inferred from UVI are consistent with those measured in-situ by the FAST spacecraft. These observations quantify the differences between global and local auroral precipitation processes and will provide a valuable experimental check for models of sudden storm commencements and magnetospheric response to perturbations in the solar wind.

  13. Danish auroral science history

    NASA Astrophysics Data System (ADS)

    Stauning, P.

    2011-01-01

    Danish auroral science history begins with the early auroral observations made by the Danish astronomer Tycho Brahe during the years from 1582 to 1601 preceding the Maunder minimum in solar activity. Included are also the brilliant observations made by another astronomer, Ole Rømer, from Copenhagen in 1707, as well as the early auroral observations made from Greenland by missionaries during the 18th and 19th centuries. The relations between auroras and geomagnetic variations were analysed by H. C. Ørsted, who also played a vital role in the development of Danish meteorology that came to include comprehensive auroral observations from Denmark, Iceland and Greenland as well as auroral and geomagnetic research. The very important auroral investigations made by Sophus Tromholt are outlined. His analysis from 1880 of auroral observations from Greenland prepared for the significant contributions from the Danish Meteorological Institute, DMI, (founded in 1872) to the first International Polar Year 1882/83, where an expedition headed by Adam Paulsen was sent to Greenland to conduct auroral and geomagnetic observations. Paulsen's analyses of the collected data gave many important results but also raised many new questions that gave rise to auroral expeditions to Iceland in 1899 to 1900 and to Finland in 1900 to 1901. Among the results from these expeditions were 26 unique paintings of the auroras made by the artist painter, Harald Moltke. The expedition to Finland was headed by Dan la Cour, who later as director of the DMI came to be in charge of the comprehensive international geomagnetic and auroral observations made during the Second International Polar Year in 1932/33. Finally, the article describes the important investigations made by Knud Lassen during, among others, the International Geophysical Year 1957/58 and during the International Quiet Sun Year (IQSY) in 1964/65. With his leadership the auroral and geomagnetic research at DMI reached a high international

  14. On the Relationship of Interplanetary Pressure Pulses and Subsequent Auroral Activity

    NASA Technical Reports Server (NTRS)

    Spann, J. F.; Smith, M.; Germany, G.; Chua, D.; Brittnacher, M.; Parks, G.

    1999-01-01

    The relation between interplanetary pressure pulses and subsequent auroral breakup is examined using over 70 cases from 1997 to 1999. A solar wind-magnetosphere coupling parameter (based on Bargatze et al., Solar Wind-Magnetosphere Coupling, Terra Scientific Publishing Co., p. 101- 109, 1986) is used to correlate the amount of energy stored in the magnetospheric to the time delay for auroral activity relative to the SW pressure enhancement.

  15. Auroral arcs and ion outflow

    NASA Astrophysics Data System (ADS)

    Maggiolo, Romain

    2016-04-01

    This presentation provides an overwiew of the chapter "Auroral Arcs and Ion Outflow" from the AGU book "Auroral Dynamics and Space Weather" (eds Y. Zhang and L. J. Paxton). This topic covers a wide range of domains, from auroral acceleration processes, auroral arc morphology and dynamics to global magnetosphere-ionosphere coupling and atmospheric erosion. This presentation mainly focuses on the observational properties of auroral ion outflow. Recent observations about their large-scale spatial distribution and link with auroral forms will be presented. Auroral ion outflow statistical dependence on solar and geomagnetic activity and its modulation by auroral dynamics at the timescale of substorms will also be discussed.

  16. Continuous auroral activity related to high speed streams with interplaneraty ALFV&N wave trains

    NASA Technical Reports Server (NTRS)

    Guarnieri, Fernando L.; Tsurutani, Bruce T.; Gonzalez, Walter D.; Kamide, Yosuke; Zhou, Xiaoyan

    2004-01-01

    We discuss a type of intense magnetospheric/auroral activity that is not always substorms: High-Intensity, Long-Duration, Continuous AE Activity (HILDCAA) events, which occur during high speed solar wind streams. The high speed streams contain large-amplitude, nonlinear Alfvtn waves. Analyses of POLAR UV images, demonstrate that the AE increases/AL decreases in HILDCAAs are not always substorm expansion phases (although some substorms may occur). The associated auroral W energy deposition is throughout a continuous (360') auroral oval. During some image intervals, the dayside aurora is the most remarkable feature. Our hypothesis is that solar wind energy transfer from the solar wind to the magnetosphere/ionosphere is primarily directly driven due to the finite wavelength Alfv6n waves and the rapid dBz/dt variability.

  17. Statistical analysis of extreme auroral electrojet indices

    NASA Astrophysics Data System (ADS)

    Nakamura, Masao; Yoneda, Asato; Oda, Mitsunobu; Tsubouchi, Ken

    2015-09-01

    Extreme auroral electrojet activities can damage electrical power grids due to large induced currents in the Earth, degrade radio communications and navigation systems due to the ionospheric disturbances and cause polar-orbiting satellite anomalies due to the enhanced auroral electron precipitation. Statistical estimation of extreme auroral electrojet activities is an important factor in space weather research. For this estimation, we utilize extreme value theory (EVT), which focuses on the statistical behavior in the tail of a distribution. As a measure of auroral electrojet activities, auroral electrojet indices AL, AU, and AE, are used, which describe the maximum current strength of the westward and eastward auroral electrojets and the sum of the two oppositely directed in the auroral latitude ionosphere, respectively. We provide statistical evidence for finite upper limits to AL and AU and estimate the annual expected number and probable intensity of their extreme events. We detect two different types of extreme AE events; therefore, application of the appropriate EVT analysis to AE is difficult.

  18. Engaging the Athabascan Native American students of Venetie, Alaska in the auroral research occurring over their village

    NASA Astrophysics Data System (ADS)

    Michell, R. G.; Powell, D.; Samara, M.; Jahn, J.; Pfeifer, M.; Ibarra, S.; Hampton, D. L.

    2012-12-01

    During February 2012, an optical auroral obversing campaign was conducted from the remote village of Venetie, located in North-central Alaska. The approximately 200 people in the village of are mostly Gwich'in Athabaskan. Venetie is in a unique location in that it is one of the only villages that has sounding rockets launched directly over it. While there for the research campaign of approximately one week, I spent several days meeting with and talking to the students about the auroral research that occurs literaly over their village. The John Fredson School in Venetie is a K-12 school and I was able to talk with all of the classes. They were very receptive and interested in science, but have very limited connectivity with the rest of the world, even with a slow internet connection at the school. Their perspective about the aurora is completely different, for them, the aurora is a nearly everyday experience in the winter and therefore they do not think much of it, much like students in the lower 48 would think of clouds. Using the internet, we were able to connect the 4th and 5th grade students in Venetie (through Skype) with a group of 4th and 5th grade students at Sunshine Cottage School for Deaf Children in San Antonio, TX. This was very successful on both ends and resulted in many ideas for future activities. We will discuss the experiences from this trip and the lessons learned for conducting K-12 outreach in such remote schools.; Dr. Michell presenting to the students in Venetie, AK. ; Tribal office building in Venetie, AK, with the aurora overhead.

  19. 19th century auroral observations reveal solar activity patterns

    NASA Astrophysics Data System (ADS)

    Silverman, Sam

    Growing interest in the aurora in the early part of the eighteenth century, which resulted from the spectacular reappearance of the aurora in 1707 and 1716, followed a relative scarcity of great auroras during the Maunder minimum, a period of prolonged reduced solar activity from about 1645-1715. Observations in the early eighteenth century led to questions about the geographical extent, nature, and temporal variability of the auroras. Typically, such observations were included as part of recorded meteorological notations, though occasionally early astronomers, such as Tycho Brahe in the 1590s, included auroras in their observations. Meteorological observations were important because of the effects of weather and climate on agriculture, and, according to the belief at the time, on disease.

  20. Variability of Mass Dependence of Auroral Acceleration Processes with Solar Activity

    NASA Technical Reports Server (NTRS)

    Ghielmetti, Arthur G.

    1997-01-01

    The objectives of this investigation are to improve understanding of the mass dependent variability of the auroral acceleration processes and so to clarify apparent discrepancies regarding the altitude and local time variations with solar cycle by investigating: (1) the global morphological relationships between auroral electric field structures and the related particle signatures under varying conditions of solar activity, and (2) the relationships between the electric field structures and particle signatures in selected events that are representative of the different conditions occurring during a solar cycle. The investigation is based in part on the Lockheed UFI data base of UpFlowing Ion (UFI) events in the 5OO eV to 16keV energy range and associated electrons in the energy range 7O eV to 24 keV. This data base was constructed from data acquired by the ion mass spectrometer on the S3-3 satellite in the altitude range of I to 1.3 Re. The launch of the POLAR spacecraft in early 1996 and successful operation of its TIMAS ion mass spectrometer has provided us with data from within the auroral acceleration regions during the current solar minimum. The perigee of POLAR is at about 1 Re, comparable to that of S3-3. The higher sensitivity and time resolution of TIMAS compared to the ion mass spectrometer on S3-3 together with its wider energy range, 15 eV to 33 keV, facilitate more detailed studies of upflowing ions.

  1. Studies of the substorm on March 12, 1991: 1. Structure of substorm activity and auroral ions

    NASA Astrophysics Data System (ADS)

    Lazutin, L. L.; Kozelova, T. V.; Meredith, N. P.; Danielides, M.; Kozelov, B. V.; Jussila, J.; Korth, A.

    2007-02-01

    The substorm on March 12, 1991 is studied using the data of ground-based network of magnetometers, all-sky cameras and TV recordings of aurora, and measurements of particle fluxes and magnetic field onboard a satellite in the equatorial plane. The structure of substorm activity and the dynamics of auroral ions of the central plasma sheet (CPS) and energetic quasi-trapped ions related to the substorm are considered in the first part. It is shown that several sharp changes in the fluxes and pitch-angle distribution of the ions which form the substorm ion injection precede a dipolarization of the magnetic field and increases of energetic electrons, and coincide with the activation of aurora registered 20° eastward from the satellite. A conclusion is drawn about different mechanisms of the substorm acceleration (injection) of electrons and ions.

  2. Auroral activity associated with Kelvin-Helmholtz instability at the inner edge of the low-latitude boundary layer

    NASA Technical Reports Server (NTRS)

    Farrugia, C. J.; Sandholt, P. E.; Burlaga, L. F.

    1994-01-01

    Auroral activity occurred in the late afternoon sector (approx. 16 MLT) in the northern hemisphere during the passage at Earth of an interplanetary magnetic cloud on January 14, 1988. The auroral activity consisted of a very dynamic display which was preceded and followed by quiet auroral displays. During the quiet displays, discrete rayed arcs aligned along the geomagnetic L shells were observed. In the active stage, rapidly evolving spiral forms centered on magnetic zenith were evident. The activity persisted for many minutes and was characterized by the absence of directed motion. They were strongly suggestive of intense filaments of upward field-aligned currents embedded in the large-scale region 1 current system. Distortions of the flux ropes as they connect from the equatorial magnetosphere to the ionosphere were witnessed. We assess as possible generating mechanisms three nonlocal sources known to be associated with field-aligned currents. Of these, partial compressions of the magnetosphere due to variations of solar wind dynamic pressure seem an unlikely source. The possibility that the auroral forms are due to reconnection is investigated but is excluded because the active aurora were observed on the closed field line region just equatorward of the convection reversal boundary. To support this conclusion further, we apply recent results on the mapping of ionospheric regions to the equatorial plane based on the Tsyganenko 1989 model (Kaufmann et al., 1993). We find that for comparable magnetic activity the aurora map to the equatorial plane at X(sub GSM) = approx. 3 R(sub E) and approx. 2 R(sub E) inward of the magnetopause, that is, the inner edge of the boundary layer close to dusk. Since the auroral forms are manifestly associated with magnetic field shear, a vortical motion at the equatorial end of the flux rope is indicated, making the Kelvin-Helmholtz instability acting at the inner edge of the low-latitude boundary layer the most probable generating

  3. Origins of the Earth's Diffuse Auroral Precipitation

    NASA Astrophysics Data System (ADS)

    Ni, Binbin; Thorne, Richard M.; Zhang, Xiaojia; Bortnik, Jacob; Pu, Zuyin; Xie, Lun; Hu, Ze-jun; Han, Desheng; Shi, Run; Zhou, Chen; Gu, Xudong

    2016-04-01

    The Earth's diffuse auroral precipitation provides the major source of energy input into the nightside upper atmosphere and acts as an essential linkage of the magnetosphere-ionosphere coupling. Resonant wave-particle interactions play a dominant role in the scattering of injected plasma sheet electrons, leading to the diffuse auroral precipitation. We review the recent advances in understanding the origin of the diffuse aurora and in quantifying the exact roles of various magnetospheric waves in producing the global distribution of diffuse auroral precipitation and its variability with the geomagnetic activity. Combined scattering by upper-and lower-band chorus accounts for the most intense inner magnetospheric electron diffuse auroral precipitation on the nightside. Dayside chorus can be responsible for the weaker dayside electron diffuse auroral precipitation. Pulsating auroras, the dynamic auroral structures embedded in the diffuse aurora, can be mainly caused by modulation of the excitation of lower band chorus due to macroscopic density variations in the magnetosphere. Electrostatic electron cyclotron harmonic waves are an important or even dominant cause for the nightside electron diffuse auroral precipitation beyond {˜}8Re and can also contribute to the occurrence of the pulsating aurora at high L-shells. Scattering by electromagnetic ion cyclotron waves could quite possibly be the leading candidate responsible for the ion precipitation (especially the reversed-type events of the energy-latitude dispersion) in the regions of the central plasma sheet and ring current. We conclude the review with a summary of current understanding, outstanding questions, and a number of suggestions for future research.

  4. Experimental studies of auroral arc generators

    SciTech Connect

    Suszcynsky, D.M.; Borovsky, J.E.; Thomsen, M.F.

    1997-08-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). An all-sky video camera system was deployed in Eagle, Alaska at the foot of the magnetic field line that threads geosynchronous satellite 1989-046 as part of a campaign to study correlations of ground-based auroral activity with satellite-based plasma and energetic particle measurements. The overall intent of the project was to study magnetosphere-ionosphere coupling as it relates to the aurora, and, in particular, to look for signatures that may help to identify various auroral generator mechanism(s). During this study, our efforts were primarily directed towards identifying the generator mechanism(s) for pulsating aurora. Our data, though not conclusive, are found to support theories that propose a cyclotron resonance mechanism for the generation of auroral pulsations.

  5. Substorm evolution of auroral structures

    NASA Astrophysics Data System (ADS)

    Partamies, N.; Juusola, L.; Whiter, D.; Kauristie, K.

    2015-07-01

    Auroral arcs are often associated with magnetically quiet time and substorm growth phases. We have studied the evolution of auroral structures during global and local magnetic activity to investigate the occurrence rate of auroral arcs during different levels of magnetic activity. The ground-magnetic and auroral conditions are described by the magnetometer and auroral camera data from five Magnetometers — Ionospheric radars — All-sky cameras Large Experiment stations in Finnish and Swedish Lapland. We identified substorm growth, expansion, and recovery phases from the local electrojet index (IL) in 1996-2007 and analyzed the auroral structures during the different phases. Auroral structures were also analyzed during different global magnetic activity levels, as described by the planetary Kp index. The distribution of auroral structures for all substorm phases and Kp levels is of similar shape. About one third of all detected structures are auroral arcs. This suggests that auroral arcs occur in all conditions as the main element of the aurora. The most arc-dominated substorm phases occur in the premidnight sector, while the least arc-dominated substorm phases take place in the dawn sector. Arc event lifetimes and expectation times calculated for different substorm phases show that the longest arc-dominated periods are found during growth phases, while the longest arc waiting times occur during expansion phases. Most of the arc events end when arcs evolve to more complex structures. This is true for all substorm phases. Based on the number of images of auroral arcs and the durations of substorm phases, we conclude that a randomly selected auroral arc most likely belongs to a substorm expansion phase. A small time delay, of the order of a minute, is observed between the magnetic signature of the substorm onset (i.e., the beginning of the negative bay) and the auroral breakup (i.e., the growth phase arc changing into a dynamic display). The magnetic onset was

  6. Auroral research at the Tromsø Northern Lights Observatory: the Harang directorship, 1928-1946

    NASA Astrophysics Data System (ADS)

    Egeland, Alv; Burke, William J.

    2016-03-01

    The Northern Lights Observatory in Tromsø began as Professor Lars Vegard's dream for a permanent facility in northern Norway, dedicated to the continuous study of auroral phenomenology and dynamics. Fortunately, not only was Vegard an internationally recognized spectroscopist, he was a great salesman and persuaded the Rockefeller Foundation that such an observatory represented an important long-term investment. A shrewd judge of talent, Vegard recognized the scientific and managerial skills of Leiv Harang, a recent graduate from the University of Oslo, and recommended that he become the observatory's first director. In 1929, subsequent to receiving the Rockefeller Foundation grant, the University of Oslo established a low temperature laboratory to support Vegard's spectroscopic investigations. This paper follows the scientific accomplishments of observatory personnel during the 18 years of Harang's directorship. These include: identifying the chemical sources of auroral emissions, discovering the Vegard-Kaplan bands, quantifying height distributions of different auroral forms, interpreting patterns of magnetic field variations, remotely probing auroral electron distribution profiles in the polar ionosphere, and monitoring the evolving states of the ozone layer. The Rockefeller Foundation judges got it right: the Tromsø Nordlysobservatoriet was, and for decades remained, an outstanding scientific investment.

  7. Altitude variations of the peak auroral emissions within auroral structures

    NASA Astrophysics Data System (ADS)

    Sangalli, L.; Partamies, N.; Gustavsson, B.

    2014-12-01

    The MIRACLE network monitors auroral activity in the Fennoscandian sector of Europe. Network stations cover the range of 55° to 57° magnetic latitude North and span two hours in magnetic local time. Some of the MIRACLE network stations include digital all-sky cameras (ASC) with overlapping field-of-views located at the latitude aurora occurs. The ASCs in this network operate at three different wavelengths: 427.8 nm (blue line), 557.7 nm (green line) and 630.0 nm (red line). These wavelengths are selected using narrow band filters. The new ASC systems are based on electron multiplying CCDs (emCCD), which allow higher time and spatial resolutions. The peak auroral emission altitude is determined using two ASC images from a station pair. Different auroral events are used to evaluate the altitude variations of the peak auroral emissions within auroral structures and its evolution in time.

  8. Altitude Variations of the Peak Auroral Emissions within Auroral Structures

    NASA Astrophysics Data System (ADS)

    Sangalli, L.

    2015-12-01

    The MIRACLE network monitors auroral activity in the Fennoscandian sector of Europe. Network stations cover the range of 55° to 57° magnetic latitude North and span two hours in magnetic local time. Some of the MIRACLE network stations include digital all-sky cameras (ASC) with overlapping field-of-views located at the latitude aurora occurs. The ASCs in this network operate at three different wavelengths: 427.8 nm (blue line), 557.7 nm (green line) and 630.0 nm (red line). These wavelengths are selected using narrow band filters. The new ASC systems are based on electron multiplying CCDs (emCCD), which allow higher time and spatial resolutions. The peak auroral emission altitude is determined using two ASC images from a station pair. Different auroral events are used to evaluate the altitude variations of the peak auroral emissions within auroral structures and its evolution in time.

  9. The application of soft X-ray imaging techniques to auroral research

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The feasibility of building and operating a grazing incidence X-ray telescope for auroral zone studies from the Polar Plasma Laboratory (PPL) is discussed. A detailed structural analysis of the preferred design, an array of seven nested Wolter mirrors, is presented. An engineering evaluation of the requirements for the instrumental configuration, power, weight and telemetry is included. The problems of radiation hardening and thermal control are discussed. The resulting strawman instrument is presented.

  10. Auroral particles

    NASA Technical Reports Server (NTRS)

    Evans, David S.

    1987-01-01

    The problems concerning the aurora posed prior to the war are now either solved in principle or were restated in a more fundamental form. The pre-war hypothesis concerning the nature of the auroral particles and their energies was fully confirmed, with the exception that helium and oxygen ions were identified as participating in the auroral particle precipitation in addition to the protons. The nature of the near-Earth energization processes affecting auroral particles was clarified. Charged particle trajectories in various electric field geometries were modeled. The physical problems have now moved from determining the nature and geometry of the electric fields, which accelerate charged particles near the Earth, to accounting for the existence of these electric fields as a natural consequence of the solar wind's interaction with Earth. Ultimately the reward in continuing the work in auroral and magnetospheric particle dynamics will be a deeper understanding of the subtleties of classical electricity and magnetism as applied to situations not blessed with well-defined and invariant geometries.

  11. Auroral kilometric radiation as an indicator of auroral magnetic disturbances

    NASA Technical Reports Server (NTRS)

    Voots, G. R.; Gurnett, D. A.; Akasofu, S.-I.

    1977-01-01

    Satellite low-frequency radio measurements have shown that auroral kilometric radiation, an intense radio emission from the earth's auroral regions, is closely associated with auroral and magnetic disturbances. In this paper a detailed investigation of this relationship is presented, using the auroral electrojet (AE) index as an indicator of auroral magnetic disturbances and radio measurements from the Imp 6 spacecraft. This study indicates that the mean power flux of the 178-kHz radiation tends to be proportional to the 1.2 power of (AE) for AE more than 100 gamma and, with less certainty, to the square of (AE) for AE less than 100 gamma. The correlation coefficient between log AE and the logarithm of the power flux is 0.514. Occasionally, a kilometric radiation event is detected which is not detected by the ground magnetometer stations, even though an auroral substorm is in progress. This study shows that the remote detection of kilometric radio emissions from the earth can be used as a reasonably reliable indicator of auroral substorm activity.

  12. Energetic auroral and polar ion outflow at DE 1 altitudes Magnitude, composition, magnetic activity dependence, and long-term variations

    NASA Technical Reports Server (NTRS)

    Yau, A. W.; Lenchyshyn, L.; Shelley, E. G.; Peterson, W. K.

    1985-01-01

    Data acquired from the Dynamics Explorer I Energetic Ion Composition Spectrometer in the period from September 1981 to May 1984 are used to determine the magnitude of the terrestrial ion outflow in the 0.01-17 keV/el range. The data are also employed to investigate the mass composition and topology (local time and invariant latitude distributions) of the ion outflow, as well as the outflow's magnetic activity dependence and long-term variation. The relative importance of auroral versus polar cap upflowing ions as a source of energetic plasma for various parts of the magnetosphere is examined.

  13. Modeled F region response to auroral dynamics based upon Dynamics Explorer auroral observations

    NASA Technical Reports Server (NTRS)

    Sojka, J. J.; Schunk, R. W.; Craven, J. D.; Frank, L. A.; Sharber, J.

    1989-01-01

    Auroral images from the Dynamics Explorer 1 (DE 1) scanning auroral imager have been combined with in situ auroral precipitation data from the DE 2 low-altitude plasma instrument, to form a time-dependent global auroral energy flux model. This model has both good time (12 min) and spatial (100 km) resolution compared to that currently available for global-scale ionospheric and thermospheric modeling. The development and comparison of this model with others are discussed. Data from an aurorally active period, November 25, 1981, are presented and used as a case study for this model. Using a global ionospheric model, the effect of the DE auroral model is contrasted with that of a conventional empirical auroral energy flux model. Major differences in the modeled F region ionosphere are predicted from this comparative study.

  14. Two substorm studies of relations between westward electric fields in the outer plasmasphere, auroral activity, and geomagnetic perturbations

    NASA Technical Reports Server (NTRS)

    Carpenter, D. L.; Akasofu, S.

    1972-01-01

    Temporal variations of the westward component of the magnetospheric convection electric field in the outer plasmasphere were compared to auroral activity near L = 7, and to variations in the geomagnetic field at middle and high latitudes. The substorms occurred on July 29, 1965 near 0530 UT and on August 20, 1965 near 0730 UT. The results on westward electric field E(w) were obtained by the whistler method using data from Eights, Antarctica (L is approximately 4). All sky camera records were obtained from Byrd, Antarctica, (L is approximately 7), located within about 1 hour of Eights in magnetic local time. It was found that E(w) within the outer plasmasphere increased rapidly to substorm levels about the time of auroral expansion at nearby longitudes. This behavior is shown to differ from results on E(w) from balloons, which show E(w) reaching enhanced levels prior to the expansion. A close temporal relation was found between the rapid, substorm associated increases in E(w) and a well known type of nightside geomagnetic perturbation. Particularly well defined was the correlation of E(w) rise and a large deviation of the D component at middle latitudes.

  15. 250 MHz/GHz scintillation parameters in the equatorial, polar, and auroral environments. Environmental research papers

    SciTech Connect

    Basu; MacKenzie, E.; Basu; Costa, E.; Fougere, P.F.

    1986-03-28

    Ionospheric scintillation effects encountered in the equatorial-anomaly crest, polar-cap, and auroral regions have been contrasted to provide information for the design and evaluation of the performance of satellite communication links in these regions. The equatorial-anomaly region is identified as the most-disturbed irregularity environment where the amplitude and phase structures of VHF/L-band scintillations are primarily dictated by the strength of scattering rather than ionospheric motion. In the anomaly region, the spectra of intense amplitude scintillations at VHF and L-band are characterized by uniform power spectral density from the lowest frequency (10 MHz) to 4 Hz at VHF and to 1 Hz at L-band and steep rolloff at higher fluctuation frequencies with power law indices of -5 to 07. Such structures are compatible with intensity decorrelation times of 0.1 and 0.3 sec at VHF and L-band frequencies, respectively. The phase spectra are described by power-law variation of psd with frequency with typical spectral indices of -2. 4. The strong scattering at VHF induces extreme phase rates of 200 deg. in 0.1 sec. The 90th percentile values of rms phase deviation at 250 MHz with 100-sec detrend are found to be 16 rads in the early evening hours whereas amplitude scintillation can cover the entire dynamic range of 30 dB not only at 250 MHz but at L-band as well.

  16. Viking investigations of auroral electrodynamical processes

    SciTech Connect

    Marklund, G. )

    1993-02-01

    Recent results from the Viking electric field experiment and their contribution to a better understanding of the aurora and of associated ionosphere-magnetosphere processes are briefly reviewed. The high-resolution electric field data have provided new and important results in a number of different areas, including auroral electrodynamics both on the arc scale size and on the global scale, the auroral acceleration process, the current-voltage relationship, substorms, and the dynamics of the polar cusp. After a short introduction presenting some of the characteristic features of the high-altitude electric field data the remainder of this paper focuses on the role of the electric field in auroral electrodynamics and in the auroral acceleration process. The relationships between the auroral emissions and the associated electric field, current, particle, and conductivity distributions are discussed for both small-scale and large-scale auroral distributions on the basis of results from Viking event studies and from numerical model studies. Particular attention is paid to ionospheric convection and field- aligned current signatures associated with northward interplanetary magnetic field (IMF) auroral distributions, such as the theta aurora or those characterized by extended auroral activity poleward of the classical auroral oval. The role of dc electric fields for the auroral acceleration process has been further investigated and clarified. Intense low-frequency electric field fluctuations (auroral acceleration process. In this frequency range the electric field appears static for the electrons but not for the ions, giving rise to a selective acceleration. Estimates of the acceleration potential based on a number of different methods generally show good agreement, providing convincing evidence of the role of dc electric fields in the auroral acceleration process.

  17. Seasonal and solar activity dependence of the generalized polar wind with low-altitude auroral ion energization

    NASA Astrophysics Data System (ADS)

    Barakat, A. R.; Schunk, R. W.; Demars, H. G.

    2003-11-01

    The effects of low-altitude energization (LAE) of ions on the dynamic behavior of the high-latitude plasma was investigated using a macroscopic particle-in-cell (mac-PIC) model. The model simulates the behavior of a plasma-filled flux tube as it drifts across the different high-latitude regions (cusp, polar cap, auroral, and subauroral regions). In addition to the LAE, the model properly accounts for gravity, electrostatic field, magnetic mirror force, ion-ion collisions, wave-particle interactions, magnetospheric electrons, and centrifugal acceleration. However, the focus here is on the effects of the LAE and their seasonal dependence. The LAE was emulated by uniform energization of the ions in the perpendicular direction as they pass through a narrow domain (200 km in altitude) that is embedded within the cusp/auroral oval region. The roles that season, solar activity, and the altitude of the LAE play, with regard to the effects of the LAE on the plasma characteristics, were studied. In particular, several simulation runs were performed for different seasons (summer/winter), for different solar activity levels, and for different altitudes of the LAE region. Comparing the results from these runs, the following conclusions can be drawn: (1) When the LAE occurs at high altitudes, where less O+ exists, it does not appreciably enhance the O+ escape flux. The O+ escape flux for LAE occurring above ˜3000 km is almost identical to the case with no LAE. (2) In the absence of LAE, the dominant source of escaping O+ occurs in the polar cap due to magnetospheric electrons. (3) Both upward and downward O+ fluxes occur at low altitudes, while only upward O+ fluxes occur at high altitudes. (4) As the plasma drifts from the polar cap into the auroral region, it is (first) depleted due to the rapid energization associated with wave-particle interactions (WPI) and then it is slowly replenished due to the effect of the LAE. (5) In general, the cases of summer-solar maximum and

  18. Seasonal and Solar Activity Dependence of the Generalized Polar Wind with Low-Altitude Auroral Ion Energization

    NASA Astrophysics Data System (ADS)

    Barakat, A. R.; Schunk, R. W.; Demars, H. G.

    2002-12-01

    The effects of low-altitude energization (LAE) of ions on the dynamic behavior of the high-latitude plasma was investigated using a macroscopic particle-in-cell (mac-PIC) model. The model simulates the behavior of a plasma-filled flux tube as it drifts across the different high-latitude regions (cusp, polar cap, auroral, and subauroral regions). In addition to the LAE, the model properly accounts for gravity, electrostatic field, magnetic mirror force, ion-ion collisions, wave-particle interactions, magnetospheric electrons, and centrifugal acceleration. However, the focus here is on the effects of the LAE and their seasonal dependence. The LAE was emulated by uniform energization of the ions in the perpendicular direction as they pass through a narrow domain (200 km in altitude) that is embedded within the cusp/auroral oval region. The roles that season, solar activity, and the altitude of the LAE play, with regard to the effects of the LAE on the plasma characteristics, were studied. In particular, several simulation runs were performed for different seasons (summer/winter), for different solar activity levels, and for different altitudes of the LAE region. Comparing the results from these runs, the following conclusions can be drawn: (1) When the LAE occurs at high altitudes, where less O+ exists, it does not appreciably enhance the O+ escape flux. The O+ escape flux for LAE occurring above ~{3000} km is almost identical to the case with no LAE; (2) In the absence of LAE, the dominant source of escaping O+ occurs in the polar cap due to magnetospheric electrons; (3) Both upward and downward O+ fluxes occur at low altitudes, while only upward O+ fluxes occur at high altitudes; (4) As the plasma drifts from the polar cap into the auroral region, it is (first) depleted due to the rapid energization associated with wave-particle interactions (WPI) and then it is slowly replenished due to the effect of the LAE; (5) In general, the cases of summer-solar maximum and

  19. Modelling of auroral electrodynamical processes: Magnetosphere to mesosphere

    NASA Technical Reports Server (NTRS)

    Chiu, Y. T.; Gorney, D. J.; Kishi, A. M.; Newman, A. L.; Schulz, M.; Walterscheid, R. L.; CORNWALL; Prasad, S. S.

    1982-01-01

    Research conducted on auroral electrodynamic coupling between the magnetosphere and ionosphere-atmosphere in support of the development of a global scale kinetic plasma theory is reviewed. Topics covered include electric potential structure in the evening sector; morning and dayside auroras; auroral plasma formation; electrodynamic coupling with the thermosphere; and auroral electron interaction with the atmosphere.

  20. Modelling of auroral electrodynamical processes: Magnetosphere to mesosphere. Final Report

    SciTech Connect

    Chiu, Y.T.; Gorney, D.J.

    1982-01-01

    Research conducted on auroral electrodynamic coupling between the magnetosphere and ionosphere-atmosphere in support of the development of a global scale kinetic plasma theory is reviewed. Topics covered include electric potential structure in the evening sector, morning and dayside auroras, auroral plasma formation, electrodynamic coupling with the thermosphere, and auroral electron interaction with the atmosphere.

  1. Evaluating auroral processes within a magnotospheric model. Final report

    SciTech Connect

    Lyons, L.R.

    1989-01-01

    A summary of the research performed is included. Topics covered include magnetospheric model; association between discrete auroras and ion precipitation from the tail current sheet; auroral arc scale sizes and structures; polar cap size variation; low-altitude auroral boundary; auroral wave-particle interactions; thermospheric interactions; and the neutral wind flywheel.

  2. On the uniqueness of linear moving-average filters for the solar wind-auroral geomagnetic activity coupling

    NASA Technical Reports Server (NTRS)

    Vassiliadis, D.; Klimas, A. J.

    1995-01-01

    The relation between the solar wind input to the magetosphere, VB(sub South), and the auroral geomagnetic index AL is modeled with two linear moving-average filtering methods: linear prediction filters and a driven harmonic oscillator in the form of an electric circuit. Although the response of the three-parameter oscillator is simpler than the filter's, the methods yield similar linear timescales and values of the prediction-observation correlation and the prediction Chi(exp 2). Further the filter responses obtained by the two methods are similar in their long-term features. In these aspects the circuit model is equivalent to linear prediction filtering. This poses the question of uniqueness and proper interpretation of detailed features of the filters such as response peaks. Finally, the variation of timescales and filter responses with the AL activity level is discussed.

  3. Itaca2 - Twin 76-ilat auroral monitors.

    NASA Astrophysics Data System (ADS)

    Massetti, S.; Candidi, M.; Cerulli-Irelli, P.; Sparapani, R.; Maggiore, M.; Philipsen, H.; Baldetti, P.; Morbidini, A.

    2003-04-01

    In August 2002, the Italian Research Council (CNR) set up a new automatic auroral monitor in Daneborg, on the North-East coast of Greenland, thanks to the support of the Progetto Nazionale Ricerche in Antartide (PNRA), and to the logistical support of the Danish Polar Center (DPC) and the Sirus-patrol (PNG). The new station is equipped with a digital all-sky camera, and it is intended to operate in conjunction with the other Italian station located in Ny-Ålesund, Svalbard: the two observatories constitute a system of twin auroral monitors, owing almost the same invariant latitude of 76°, which is mainly devoted to the observation of the dayside red aurora connected to the cusp/LLBL magnetospheric region. When observing the high altitude dayside auroras, the field-of-views of the two stations are contiguous and allow the monitoring of the dayside auroral activity over about 80° of magnetic longitude (about 5/6 hours MLT). Since many years ago, Svalbard Islands have been an ideal place for polar researches due to its scientific facilities, the easy access during all the year and the frequent flight connections. In Greenland, on the contrary, the set up and maintenance of a high-latitude station that has to operate during the winter season, needs more logistical efforts, and it would be impossible without the precious support of people residing in-situ.

  4. Using a tag team of undergraduate researchers to construct an empirical model of auroral Poynting flux, from satellite data

    NASA Astrophysics Data System (ADS)

    Cosgrove, R. B.; Bahcivan, H.; Klein, A.; Ortega, J.; Alhassan, M.; Xu, Y.; Chen, S.; Van Welie, M.; Rehberger, J.; Musielak, S.; Cahill, N.

    2012-12-01

    Empirical models of the incident Poynting flux and particle kinetic energy flux, associated with auroral processes, have been constructed using data from the FAST satellite. The models were constructed over a three-year period by a tag-team of three groups of undergraduate researchers from Worcester Polytechnic Institute (WPI), working under the supervision of researchers at SRI International, a nonprofit research institute. Each group spent one academic quarter in residence at SRI, in fulfillment of WPI's Major Qualifying Project (MQP), required for graduation from the Department of Electrical and Computer Engineering. The MQP requires a written group report, which was used to transition from one group to the next. The student's research involved accessing and processing a data set of 20,000 satellite orbits, replete with flaws associated with instrument failures, which had to be removed. The data had to be transformed from the satellite reference frame into solar coordinates, projected to a reference altitude, sorted according to geophysical conditions, and etc. The group visits were chaperoned by WPI, and were jointly funded. Researchers at SRI were supported by a grant from the National Science Foundation, which was tailored to accommodate the undergraduate tag-team approach. The NSF grant extended one year beyond the student visits, with increased funding in the final year, permitting the researchers at SRI to exercise quality control, and to produce publications. It is expected that the empirical models will be used as inputs to large-scale general circulation models (GCMs), to specify the atmospheric heating rate at high altitudes.; Poynting Flux with northward IMF ; Poynting flux with southward IMF

  5. Dependence of the high-latitude plasma irregularities on the auroral activity indices: a case study of 17 March 2015 geomagnetic storm

    NASA Astrophysics Data System (ADS)

    Cherniak, Iurii; Zakharenkova, Irina

    2015-09-01

    The magnetosphere substorm plays a crucial role in the solar wind energy dissipation into the ionosphere. We report on the intensity of the high-latitude ionospheric irregularities during one of the largest storms of the current solar cycle—the St. Patrick's Day storm of 17 March 2015. The database of more than 2500 ground-based Global Positioning System (GPS) receivers was used to estimate the irregularities occurrence and dynamics over the auroral region of the Northern Hemisphere. We analyze the dependence of the GPS-detected ionospheric irregularities on the auroral activity. The development and intensity of the high-latitude irregularities during this geomagnetic storm reveal a high correlation with the auroral hemispheric power and auroral electrojet indices (0.84 and 0.79, respectively). Besides the ionospheric irregularities caused by particle precipitation inside the polar cap region, evidences of other irregularities related to the storm enhanced density (SED), formed at mid-latitudes and its further transportation in the form of tongue of ionization (TOI) towards and across the polar cap, are presented. We highlight the importance accounting contribution of ionospheric irregularities not directly related with particle precipitation in overall irregularities distribution and intensity.

  6. Research Activities.

    ERIC Educational Resources Information Center

    Santa Fe Community Coll., Gainesville, FL.

    The five parts of this report are: research on instruction; faculty dissertations; inter-institutional research; in-college research; and college-endorsed research. The first covers experiments in teaching French, practical nursing, English, math, and chemistry, and in giving examinations. Faculty dissertations include studies of post-graduate…

  7. Trigger, an active release experiment that stimulated auroral particle precipitation and wave emissions

    NASA Technical Reports Server (NTRS)

    Holmgren, G.; Bostroem, R.; Kelley, M. C.; Kintner, P. M.; Lundin, R.; Fahleson, U. V.; Bering, E. A.; Sheldon, W. R.

    1979-01-01

    The experiment design, including a description of the diagnostic and chemical release payload, and the general results are given for an auroral process simulation experiment. A drastic increase of the field aligned charged particle flux was observed over the approximate energy range 10 eV to more than 300 keV, starting about 150 ms after the release and lasting about one second. The is evidence of a second particle burst, starting one second after the release and lasting for tens of seconds, and evidence for a periodic train of particle bursts occurring with a 7.7 second period from 40 to 130 seconds after the release. A transient electric field pulse of 200 mv/m appeared just before the particle flux increase started. Electrostatic wave emissions around 2 kHz, as well as a delayed perturbation of the E-region below the plasma cloud were also observed. Some of the particle observations are interpreted in terms of field aligned electrostatic acceleration a few hundred kilometers above the injected plasma cloud. It is suggested that the acceleration electric field was created by an instability driven by field aligned currents originating in the plasma cloud.

  8. Modeled F region response to auroral dynamics based up dynamics explorer auroral observations

    SciTech Connect

    Sojka, J.J.; Schunk, R.W. ); Craven, J.D.; Frank, L.A.; Sharber, J.; Winningham, J.D.

    1989-07-01

    Auroral images from the Dynamiccs Explorer 1 (DE 1) scanning auroral imager have been combined with in situ auroral precipitation data from the DE 2 low altitude plasma instrument to form a time-dependent global auroral energy flux model. This model has both good time (12 min) and spatial (100 km) resolution compared to that currently available for global scale ionospheric and thermospheric modeling. The development and comparison of this model with others are discussed. Data from an aurorally active period, November 25, 1981, are presented and used as a case study for this model. Using a global ionospheric model, the effect of the DE auroral model is contrasted with that of a conventional empirical auroral energy flux model. Major differences in the modeled {ital F} region ionosphere are predicted from this comparative study. Specifically, {ital F} region densities differ by factors of two to four, while density boundary locations differ by up to 5{degree} in latitude. The results indicate that pixel size'' auroral fine-structure must be included in the global ionosphere and thermosphere models when they are tested against specific ground-based or satellite data sets if an unambiguous result is to be obtained. The longer time constants of the {ital F} region are not enough to smooth-out the auroral (spatial and temporal) dynamics. {copyright} American Geophysical Union 1989

  9. Auroral precipitation caused by auroral kilometric radiation

    NASA Technical Reports Server (NTRS)

    Calvert, W.

    1987-01-01

    If the auroral kilometric radiation (AKR) were generated by loss cone lasing on closed field lines, as has been proposed, then it should cause substantial auroral precipitation by the pitch angle scattering of energetic electrons into the loss cone. A rough estimate for this precipitation, based upon the observed AKR amplitudes, would imply a flux of at least 2 x 10 to the 8th el/sq cm sec over the projected ionospheric footprint of an individual laser and, if most of the AKR radio lasers occupied the same electron drift an L shell, an arc of 8 km width with a minimum average flux of roughly 10 to the 9th el/sq cm sec. It is believed that this will account for auroral arcs and other aspects of auroral electron precipitation.

  10. Characteristics of solar wind control on Jovian UV auroral activity deciphered by long-term Hisaki EXCEED observations: Evidence of preconditioning of the magnetosphere?

    NASA Astrophysics Data System (ADS)

    Kita, Hajime; Kimura, Tomoki; Tao, Chihiro; Tsuchiya, Fuminori; Misawa, Hiroaki; Sakanoi, Takeshi; Kasaba, Yasumasa; Murakami, Go; Yoshioka, Kazuo; Yamazaki, Atsushi; Yoshikawa, Ichiro; Fujimoto, Masaki

    2016-07-01

    While the Jovian magnetosphere is known to have the internal source for its activity, it is reported to be under the influence of the solar wind as well. Here we report the statistical relationship between the total power of the Jovian ultraviolet aurora and the solar wind properties found from long-term monitoring by the spectrometer EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) on board the Hisaki satellite. Superposed epoch analysis indicates that auroral total power increases when an enhanced solar wind dynamic pressure hits the magnetosphere. Furthermore, the auroral total power shows a positive correlation with the duration of a quiescent interval of the solar wind that is present before a rise in the dynamic pressure, more than with the amplitude of dynamic pressure increase. These statistical characteristics define the next step to unveil the physical mechanism of the solar wind control on the Jovian magnetospheric dynamics.

  11. Waterhole: An auroral-ionosphere perturbation experiment

    NASA Astrophysics Data System (ADS)

    Whalen, B. A.; Yau, A. W.; Creutzberg, F.; Pongratz, M. B.

    A sounding rocket carrying 100 kg of high explosives and plasma diagnostic instrumentation was launched from Churchill Research Range on 6 April 1980 over a premidnight auroral arc. The object of the experiment was to produce an ionospheric hole or plasma density depletion at about 300 km altitude on field lines connected to an auroral arc. The plasma depletion is produced when the explosive by-products (mostly water) charge-exchange with the ambient O+ ions and then rapidly recombine. It was speculated that the presence of the "hole" would interfere with the field-aligned current systems associated with the arc and would in turn perturb the auroral source mechanism. The release occurred about 10 km poleward of the auroral arc fieldlines. As expected, a large ionospheric hole was detected by rocket-borne plasma sensors. Within a few seconds following the release (a) the energetic electron precipitation observed in the hole dropped to background levels, (b) the luminosity of the auroral arc observed by a ground-based auroral scanning photometer decreased by a factor of two, and (c) the ionospheric E region density below the hole decayed at a rate consistent with a sudden reduction in particle precipitation. The simultaneous onset of these gross changes in electron precipitation coincident with the release strongly suggests a cause and effect relationship. In particular, these results suggest that the ionospheric plasma and the field-aligned current systems play a crucial role in the auroral acceleration process.

  12. Auroral Phenomena in Brown Dwarf Atmospheres

    NASA Astrophysics Data System (ADS)

    Pineda, J. Sebastian; Hallinan, Gregg

    2016-01-01

    Since the unexpected discovery of radio emission from brown dwarfs some 15 years ago, investigations into the nature of this emission have revealed that, despite their cool and neutral atmospheres, brown dwarfs harbor strong kG magnetic fields, but unlike the warmer stellar objects, they generate highly circularly polarized auroral radio emission, like the giant planets of the Solar System. Our recent results from Keck LRIS monitoring of the brown dwarf LSR1835+32 definitively confirm this picture by connecting the auroral radio emission to spectroscopic variability at optical wavelengths as coherent manifestations of strong large-scale magnetospheric auroral current systems. I present some of the results of my dissertation work to understand the nature brown dwarf auroral phenomena. My efforts include a survey of Late L dwarfs and T dwarfs, looking for auroral Hα emission and a concurrent survey looking for the auroral emission of H3+ from brown dwarfs with radio pulse detections. I discuss the potential connection of this auroral activity to brown dwarf weather phenomena and how brown dwarf aurorae may differ from the analogous emission of the magnetized giant planets in the Solar System.

  13. Auroral substorms as an electrical discharge phenomenon

    NASA Astrophysics Data System (ADS)

    Akasofu, Syun-Ichi

    2015-12-01

    During the last 50 years, we have made much progress in studying auroral substorms (consisting of the growth phase, the expansion phase, and the recovery phase). In particular, we have quantitatively learned about auroral substorms in terms of the global energy input-output relationship. (i) What powers auroral substorms? (ii) Why is there a long delay (1 h) of auroral activities after the magnetosphere is powered (growth phase)? (iii) How much energy is accumulated and unloaded during substorms? (iv) Why is the lifetime of the expansion phase so short (1h)? (v) How is the total energy input-output relationship? (vi) Where is the magnetic energy accumulated during the growth phase? On the basis of the results obtained in (i)-(vi), we have reached the following crucial question: (vii) how can the unloaded energy produce a secondary dynamo, which powers the expansion phase? Or more specifically, how can the accumulated magnetic energy get unloaded such that it generates the earthward electric fields needed to produce the expansion phase of auroral substorms? It is this dynamo and the resulting current circuit that drive a variety of explosive auroral displays as electrical discharge phenomena during the expansion phase, including the poleward advance of auroral arcs and the electrojet. This chain of processes is summarized in Section 4.2. This is the full version of work published by Akasofu (2015).

  14. Characterization and diagnostic methods for geomagnetic auroral infrasound waves

    NASA Astrophysics Data System (ADS)

    Oldham, Justin J.

    Infrasonic perturbations resulting from auroral activity have been observed since the 1950's. In the last decade advances in infrasonic microphone sensitivity, high latitude sensor coverage, time series analysis methods and computational efficiency have elucidated new types of auroral infrasound. Persistent periods of infrasonic activity associated with geomagnetic sub-storms have been termed geomagnetic auroral infrasound waves [GAIW]. We consider 63 GAIW events recorded by the Fairbanks, AK infrasonic array I53US ranging from 2003 to 2014 and encompassing a complete solar cycle. We make observations of the acoustic features of these events alongside magnetometer, riometer, and all-sky camera data in an effort to quantify the ionospheric conditions suitable for infrasound generation. We find that, on average, the generation mechanism for GAIW is confined to a region centered about ~60 0 longitude east of the anti-Sun-Earth line and at ~770 North latitude. We note furthermore that in all cases considered wherein imaging riometer data are available, that dynamic regions of heightened ionospheric conductivity periodically cross the overhead zenith. Consistent features in concurrent magnetometer conditions are also noted, with irregular oscillations in the horizontal component of the field ubiquitous in all cases. In an effort to produce ionosphere based infrasound free from the clutter and unknowns typical of geophysical observations, an experiment was undertaken at the High Frequency Active Auroral Research Program [HAARP] facility in 2012. Infrasonic signals appearing to originate from a source region overhead were observed briefly on 9 August 2012. The signals were observed during a period when an electrojet current was presumed to have passed overhead and while the facilities radio transmitter was periodically heating the lower ionosphere. Our results suggest dynamic auroral electrojet currents as primary sources of much of the observed infrasound, with

  15. The enigma of auroral spirals

    NASA Astrophysics Data System (ADS)

    Haerendel, G.

    One of the most spectacular forms that the aurora borealis can assume is the large-scale spiral Spirals are dominantly observed along the poleward boundary of the auroral oval during active periods Two concepts have been pursued in explaining their origin and in particular the counterclockwise sense of rotation of the luminous structures when viewed along the magnetic field direction An essentially magnetostatic theory following Hallinan 1976 attributes the spiral pattern to the twisting of field-lines caused by a centrally located upward field-aligned current According to Oguti 1981 and followers a clockwise rotation of the plasma flow produces the anticlockwise structure There are observations seemingly confirming or contradicting either theory In this paper it is argued that both concepts are insufficient in that only parts of the underlying physics are considered Besides field-aligned currents and plasma flow one has to take into at least two further aspects The ionospheric conductivity modified by particle precipitation has an impact on the magnetospheric plasma dynamics Furthermore auroral arcs are not fixed entities subject to distortions by plasma flows or twisted field-lines but sites of transient releases of energy We suggest that auroral spirals are ports of entry or exit of plasma into or out of the auroral oval This way it can be understood why a clockwise plasma flow can create an anticlockwise luminous pattern

  16. Vlasov simulations of auroral processes

    NASA Astrophysics Data System (ADS)

    Gunell, H.; De Keyser, J. M.; Mann, I.

    2013-12-01

    In the auroral zone, electric fields that are parallel to the magnetic field are known to exist. These fields contribute to the acceleration of the electrons that cause the auroral emissions. Thus, parallel electric fields form an integral part of the auroral current circuit. Transverse electric fields at high altitude result in parallel electric fields as a consequence of the closure of the field aligned currents through the conducting ionosphere. The parallel electric fields can be supported by the magnetic mirror field, by electric double layers, or both. We present Vlasov simulations of the plasma on a magnetic field line from the equatorial magnetosphere to the auroral ionosphere. In the upward current region, we find that about two thirds of the total voltage is concentrated in a stationary double layer at an altitude of about one earth radius. In the downward current region, double layers form and move upward not reaching a steady state. For equal currents in the two regions, the voltage is significantly lower in the downward than in the upward current region. Waves on electron time scales and vortices in electron phase space form on the high potential side of the double layers in the downward current region. Finally, we discuss how laboratory experiments can be used to simulate auroral acceleration and present computer simulations of a possible a laboratory configuration. This work was supported by the Belgian Science Policy Office through the Solar-Terrestrial Centre of Excellence and by PRODEX/Cluster PEA 90316. This research was conducted using the resources of the High Performance Computing Center North (HPC2N) at Umeå University in Sweden.

  17. Cusp/cleft auroral activity in relation to solar wind dynamic pressure, interplanetary magnetic field B(sub z) and B(sub y)

    NASA Technical Reports Server (NTRS)

    Sandholt, P. E.; Farrugia, C. J.; Burlaga, L. F.; Holtet, J. A.; Moen, J.; Lybekk, B.; Jacobsen, B.; Opsvik, D.; Egeland, A.; Lepping, R.

    1994-01-01

    Continuous optical observations of cusp/cleft auroral activities within approximately equal to 09-15 MLT and 70-76 deg magnetic latitude are studied in relation to changes in solar wind dynamic pressure and interplanetary magnetic field (IMF) variability. The observed latitudinal movements of the cusp/cleft aurora in response to IMF B(sub z) changes may be explained as an effect of a variable magnetic field intensity in the outer dayside magnetosphere associated with the changing intensity of region 1 field-aligned currents and associated closure currents. Ground magnetic signatures related to such currents were observed in the present case (January 10, 1993). Strong, isolated enhancements in solar wind dynamic pressure (Delta p/p is greater than or equal to 0.5) gave rise to equatorward shifts of the cusp/cleft aurora, characteristic auroral transients, and distinct ground magnetic signatures of enhanced convection at cleft latitudes. A sequence of auroral events of approximately equal to 5-10 min recurrence time, moving eastward along the poleward boundary of the persistent cusp/cleft aurora in the approximately equal to 10-14 MLT sector, during negative IMF B(sub z) and B(sub y) conditions, were found to be correlated with brief pulses in solar wind dynamic pressure (0.1 is less than Delta p/p is less than 0.5). Simultaneous photometer observations from Ny Alesund, Svalbard, and Danmarkshavn, Greenland, show that the events often appeared on the prenoon side (approximately equal to 10-12 MLT), before moving into the postnoon sector in the case we study here, when IMF B(sub y) is less than 0. In other cases, similar auroral event sequences have been observed to move westward in the prenoon sector, during intervals of positive B(sub y). Thus a strong prenoon/postnoon asymmetry of event occurence and motion pattern related to the IMF B(sub y) polarity is observed. We find that this category of auroral event sequence is stimulated bursts of electron precipitation

  18. GPS phase scintillation correlated with auroral forms

    NASA Astrophysics Data System (ADS)

    Hampton, D. L.; Azeem, S. I.; Crowley, G.; Santana, J.; Reynolds, A.

    2013-12-01

    The disruption of radio wave propagation due to rapid changes in electron density caused by auroral precipitation has been observed for several decades. In a few cases the disruption of GPS signals has been attributed to distinct auroral arcs [Kintner, 2007; Garner, 2011], but surprisingly there has been no systematic study of the characteristics of the auroral forms that cause GPS scintillation. In the Fall of 2012 ASTRA deployed four CASES GPS receivers at UAF observatories in Alaska (Kaktovik, Fort Yukon, Poker Flat and Gakona) specifically to address the effects of auroral activity on the high latitude ionosphere. We have initiated an analysis that compares the phase scintillation, recorded at high cadence, with filtered digital all-sky camera data to determine the auroral morphology and electron precipitation parameters that cause scintillation. From correlation studies from a single site (Poker Flat), we find that scintillation is well correlated with discrete arcs that have high particle energy flux (power per unit area), and not as well correlated with pulsating forms which typically have high characteristic energy, but lower energy flux . This indicates that the scintillation is correlated with the magnitude of the change in total electron density as expected. We will also report on ongoing work where we correlate the scintillation from the Fort Yukon receiver with the all-sky images at Poker Flat to determine the altitude that produces the greatest disturbance. These studies are aimed at a model that can predict the expected local disturbance to navigation due to auroral activity.

  19. Ionospheric scintillations/TEC and in-situ density measurements at an auroral location in the European sector. Environmental research papers, 2 October 1986-31 July 1987

    SciTech Connect

    MacKenzie, E.; Basu, S.

    1987-08-14

    The orbiting HiLat satellite launched in 1983 offered an opportunity for studying ionospheric scintillation parameters in relation to in-situ measurements of ionization density, drift velocity, field-aligned current, and particle precipitation during the sunspot-minimum period. This report discusses results of a morphological study based on observations of scintillations and total electron content (TEC) at the auroral-oval station at Tromso, Norway, during the period Dec 1983 - Oct 1985. The geometrical enhancement of scintillations observed during alignment of the propagation with the local magnetic L-shell is shown to be the most consistent and conspicuous feature of scintillations in the nighttime auroral oval. The dynamics of the spatial and temporal extent of this region are illustrated in the invariant latitude/magnetic local time grid. Steepening of phase spectral slope in the geometrical enhancement region is indicative of the presence of L-shell aligned sheet-like irregularities at long scale lengths. The seasonal variation of TEC determined from the differential Doppler measurements of HiLat transmissions is discussed in relation to the in-situ density measurements at 830 km. The results are also used to illustrate the dependence of ionospheric structure parameters on short-term variability of solar activity during the sunspot-minimum period. This study provides an insight into the nature of magnetospheric coupling with the ionosphere at high latitudes.

  20. Effects of interplanetary magnetic field azimuth on auroral zone and polar cap magnetic activity

    NASA Technical Reports Server (NTRS)

    Burch, J. L.

    1972-01-01

    During relatively quiet times in the period 1964-1968, AE is found to be greater when the interplanetary magnetic field (b sub IMF) is directed toward the sun in Jan., Feb., and Apr., and when B sub IMF is directed away from the sun in Oct. to Dec. Using Murmansk hourly H values and the AE components, AU and AL, it is shown that this sector dependence is present only in the negative H deviations. This observation supports the idea that negative bay magnitudes are determined chiefly by particle-produced ionization, while positive bay magnitudes are rather insensitive to increases in particle precipitation. The ratio of DP2-type magnetic activity in the southern polar cap to that in the northern polar cap is found to be greater by a factor of about 1.75 for B sub IMF toward the sun.

  1. Auroral activities observed by SNPP VIIRS day/night band during a long period geomagnetic storm event on April 29-30, 2014

    NASA Astrophysics Data System (ADS)

    Shao, Xi; Cao, Changyong; Liu, Tung-chang; Zhang, Bin; Wang, Wenhui; Fung, Shing F.

    2015-10-01

    The Day/Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard Suomi-NPP represents a major advancement in night time imaging capabilities. The DNB senses radiance that can span 7 orders of magnitude in one panchromatic (0.5-0.9 μm) reflective solar band and provides imagery of clouds and other Earth features over illumination levels ranging from full sunlight to quarter moon. When the satellite passes through the day-night terminator, the DNB sensor is affected by stray light due to solar illumination on the instrument. With the implementation of stray light correction, stray light-corrected DNB images enable the observation of aurora occurred in the high latitude regions during geomagnetic storms. In this paper, DNB observations of auroral activities are analyzed during a long period (> 20 hours) of geomagnetic storm event occurred on Apr. 29-30, 2014. The storm event has the Bz component of interplanetary magnetic field (IMF) pointing southward for more than 20 hours. During this event, the geomagnetic storm index Dst reached -67 nT and the geomagnetic auroral electrojet (AE) index increased and reached as high as 1200 nT with large amplitude fluctuations. The event occurred during new moon period and DNB observation has minimum moon light contamination. During this event, auroras are observed by DNB for each orbital pass on the night side (~local time 1:30am) in the southern hemisphere. DNB radiance data are processed to identify regions of aurora during each orbital pass. The evolution of aurora is characterized with time series of the poleward and equatorward boundary of aurora, area, peak radiance and total light emission of the aurora in DNB observation. These characteristic parameters are correlated with solar wind and geomagnetic index parameters. It is found that the evolution of total area-integrated radiance of auroral region over the southern hemisphere correlated well with the ground geomagnetic AE index with correlation

  2. Relativistic Electron Acceleration during High Intensity Auroral Activities: Maximum Energy Level Dependence

    NASA Astrophysics Data System (ADS)

    Hajra, Rajkumar; Tsurutani, Bruce; Echer, Ezequiel; Gonzalez, Walter

    2015-04-01

    Radiation belt relativistic (E > 0.6, > 2.0, and > 4.0 MeV) electron acceleration at geosynchronous orbit is studied for solar cycle 23 (1995-2008). High-intensity, long-duration, continuous AE activity (HILDCAA) events are considered as the basis of the analyses. Cluster-4 passes were examined for electromagnetic chorus waves in the 5 < L < 10 and 0 < MLT < 12 region. All the HILDCAA events under study were found to be characterized by enhanced whistler-mode chorus waves and flux enhancements of magnetospheric relativistic electrons of all three energies compared to the pre-event flux levels. The response of the energetic electrons to HILDCAAs was found to vary with solar cycle phase. The initial electron fluxes were lower for events occurring during the ascending and solar maximum (AMAX) phases than for events occurring during the descending and solar minimum (DMIN) phases. The flux increases for the DMIN-phase events were > 50% larger than for the AMAX-phase events. It is concluded that electrons are accelerated to relativistic energies most often and most efficiently during the DMIN-phases of the solar cycle. We propose two possible solar UV-related mechanisms to explain this solar cycle effect. Enhanced E > 0.6 MeV electron fluxes at geosynchronous orbit were first detected ~1 day after the statistical onset of HILDCAAs, E > 2.0 MeV electrons after ~1.5 days, and E > 4.0 MeV electrons after ~2.5 days. We estimated acceleration and decay rates and timescales for the three energy levels, which will be provided for wave-particle investigators to attempt to match their models to empirically derived values.

  3. Intense Auroral Activity (HILDCAAs) Observation as a Predictor of Radiation Belt Relativistic Electrons

    NASA Astrophysics Data System (ADS)

    Hajra, R.; Tsurutani, B.; Echer, E.

    2015-12-01

    Relativistic (E > 0.6, > 2.0, and > 4.0 MeV) electrons at geosynchronous orbit during solar cycle 23 are well-correlated with the intervals of high-intensity, long-duration, continuous AE activity (HILDCAA) events. Cluster-4 passes were examined for electromagnetic chorus waves in the 5 < L < 10 and 0 < MLT < 12 region. All the HILDCAA events under study were found to be characterized by enhanced whistler-mode chorus waves and flux enhancements of magnetospheric relativistic electrons of all three energies compared to the pre-event flux levels. CIR magnetic storms followed by HILDCAA events show almost the same relativistic electron signatures. It is concluded that the CIR storms have little to do with the acceleration of relativistic electrons. The response of the energetic electrons to HILDCAAs was found to vary with solar cycle phase. The initial electron fluxes were lower for events occurring during the ascending and solar maximum (AMAX) phases than for events occurring during the descending and solar minimum (DMIN) phases. The flux increases for the DMIN-phase events were > 50% larger than for the AMAX-phase events. It is concluded that electrons are accelerated to relativistic energies most often and most efficiently during the DMIN-phases of the solar cycle. Enhanced E > 0.6 MeV electron fluxes at geosynchronous orbit were first detected ~1 day after the statistical onset of HILDCAAs, E > 2.0 MeV electrons after ~1.5 days, and E > 4.0 MeV electrons after ~2.5 days. It is proposed that relativistic electrons are bootstrapped from high energy electrons: the E > 0.6 MeV electrons are accelerated from HILDCAA-injected E ~100 keV electrons, the E > 2.0 MeV electrons from the E > 0.6 MeV electron population, and consequently the E > 4.0 MeV electrons are accelerated from the E > 2.0 MeV population, etc. Relativistic electron acceleration and decay timescales will be provided for wave-particle investigators to attempt to match their models to empirically derived

  4. Orientation of the HAARP ELF ionospheric dipole and the auroral electrojet

    NASA Astrophysics Data System (ADS)

    Cohen, M. B.; Gołkowski, M.; Inan, U. S.

    2008-01-01

    The HF heating facility of the High Frequency Active Auroral Research Program (HAARP), located near Gakona, Alaska, generates ELF (300 Hz - 3 kHz) waves via modulated HF (2.7-10 MHz) heating of the auroral electrojet. Using two ELF/VLF receivers at ~700 km from HAARP, the orientation of the equivalent ELF radiating ionospheric dipole is inferred from the relative strength and Earth-ionosphere waveguide modal content of signals received. In several cases analyzed the effective HAARP electric dipole orientation is generally along magnetic east-west direction. A new metric is introduced to evaluate the validity of the determination of source characteristics with medium and long-range ELF/VLF measurements. Results are put into context of the auroral electrojet, indicating the possibility of studying small-scale electrojet structure not observable with magnetometers.

  5. Distribution of auroral surges in the evening sector

    SciTech Connect

    Kidd, S.R.; Rostoker, G. )

    1991-04-01

    Over the past dacades a large statistical data base has been gathered consisting of both ground-based magnetometer and all-sky camera records from which researchers have inferred the distribution of substorm expansive phase events across the nighttime sector. Almost without exception, the activity distribution has been based on single station data acquired over periods of years. However, to truly establish the occurrence frequency of substorm expansive phase events, it is necessary to view the entire nighttime sector instantaneously in the light of evidence which shows that more than one expansive phase disturbance can be in progress across the broad expanse of the evening sector. In this paper, the authors study the distribution of regions of localized auroral luminosity in the poleward portion of the evening sectorauroral oval using images in the ultraviolet portion of the auroral spectrum acquired by the Viking satellite over 9 months in 1986. They find that auroral surge activity peaks in the hour before local magnetic midnight, with the probability of detecting a surge steadily decreasing to 10% of the probability of finding a surge in the hour prior to midnight as one moves westward towards 1,900 MLT. They show that their conclusion is not dependent on the threshold chosen for surge identification over a reasonable portion of the intensity range covered by the Viking imager. They further show that for the interval of several months near sunspot minimum in 1986 there is better than a 90% chance that no surge will be detected in a 1-hour range of magnetic local time if one were to sample that segment of the auroral oval at any arbitrary time.

  6. Auroral Spatial Structures Probe Sub-Orbital Mission Preliminary Results

    NASA Astrophysics Data System (ADS)

    Pratt, J.; Swenson, C.; Martineau, R. J.; Fish, C. S.; Conde, M.; Hampton, D.; Crowley, G.

    2015-12-01

    The NASA Auroral Spatial Structures Probe, 49.002, was launched January 28, 2015 from the Poker Flat Research Range into active aurora over the northern coast of Alaska. The primary objective of this mission was to determine the contribution of small spatial and temporal scale fluctuations of the electric fields to the larger-scale energy deposition processes associated with the aurora. The Auroral Spatial Structures Probe Sub-Orbital Mission consisted of a formation of 7 spacecraft (a main payload with 6 deployable sub-payloads) designed for multiple temporally spaced co-located measurements of electric and magnetic fields in the earth's ionosphere. The mission was able to make observations at a short time scale and small spatial scale convergence that is unobservable by either satellite or ground-based observations. The payloads included magnetometers, electric field double probes, and Langmuir probes as well as a sweeping impedance probe on the main payload. We present here preliminary results from the measurements taken that hint at the underlying spatial structure of the currents and energy deposition in the aurora. The Poynting flux derived from the observations is shown and implications are discussed in terms of the contribution of small spatial scale, rapid temporal scale fluctuations in the currents that deposit energy in the auroral region. Funding provided by NASA Grants NNX11AE23G and NNX13AN20A.

  7. The auroral plasma cavity

    NASA Technical Reports Server (NTRS)

    Calvert, W.

    1981-01-01

    A region of diminished plasma density has been found to occur at the source of auroral kilometric radiation (AKR). The density within this auroral plasma cavity, determined from limited Hawkeye wave data, was less than 1/cu cm from 1.8 to 3 earth radii geocentric, at 70 deg + or - 3 deg invariant magnetic latitude. The altitude variation of the magnetic field produces a minimum in the ratio of plasma frequency to cyclotron frequency within the cavity which accounts for the observed spectrum of AKR.

  8. Transient auroral emissions at Jupiter and Saturn associated with magnetic reconnection (Arne Richter Award for Outstanding Young Scientists Lecture)

    NASA Astrophysics Data System (ADS)

    Radioti, A.

    2012-04-01

    The auroral activity is the visible signature of a long chain of interactions and provides a picture of the magnetospheric processes. Ionospheric and magnetospheric coupling at Jupiter and Saturn associated with magnetospheric processes such as magnetic reconnection gives rise to precipitating energetic particles and auroral emissions. This lecture discusses the auroral dynamics with emphasis on the auroral counterpart of magnetic reconnection at Jupiter and Saturn, based on combined studies of remote auroral, in-situ magnetospheric data and simulations. In particular it is shown that periodic ejected plasma flow during magnetic reconnection in Jupiter's tail couples with the ionosphere and creates periodic auroral features. At Saturn, plasma flow produced by consecutive reconnection events in the flank of the magnetopause creates transient auroral emissions at the end of the ionospheric footprint of the newly open field lines. Finally, injected plasma populations in the magnetosphere, possibly associated with magnetic reconnection, trigger auroral features located equatorward of the main auroral ring of emission at Saturn.

  9. Observations of a gradual transition between Ps 6 activity with auroral torches and surgelike pulsations during strong geomagnetic disturbances

    NASA Technical Reports Server (NTRS)

    Steen, A.; Collis, P. N.; Evans, D.; Kremser, G.; Capelle, S.; Rees, D.; Tsurutani, B. T.

    1988-01-01

    This paper describes a long-lasting large-amplitude pulsation event, which occurred on January 10, 1983 in the ionosphere and magnetosphere and was characterized by Steen and Rees (1983). Over the 4-h period (0200-0600 UT), the characteristics of the pulsations in the ionosphere changed from being Ps 6 auroral torches toward substorms and back to Ps 6. At GEO, the corresponding characteristics were a modulation of the high-energy particle intensity and plasma dropouts. Based on the ideas presented by Rostoker and Samson (1984), an interpretation of the event is offered, according to which the pulsations are caused by the Kelvin-Helmholtz instability during an interval of strong magnetospheric convection. On the basis of this explanation, a new interpretation of the substorm time sequence is proposed.

  10. Magnetospheric and auroral plasmas - A short survey of progress

    NASA Technical Reports Server (NTRS)

    Frank, L. A.

    1975-01-01

    Important milestones in our researches of auroral and magnetospheric plasmas for the past quadrennium 1971-1975 are reviewed. Many exciting findings, including those of the polar cusp, the polar wind, the explosive disruptions of the magnetotail, the interactions of hot plasmas with the plasmapause, the auroral field-aligned currents, and the striking inverted V electron precipitation events, were reported during this period. Solutions to major questions concerning the origins and acceleration of these plasmas appear possible in the near future. A comprehensive bibliography of current research is appended to this brief survey of auroral and magnetospheric plasmas.

  11. Correlation Between Low Frequency Auroral Kilometric Radiation (AKR) and Auroral Structures

    NASA Technical Reports Server (NTRS)

    Paxamickas, Katherine A.; Green, James L.; Gallagher, Dennis L.; Boardsen, Scott; Mende, Stephen; Frey, Harald; Reinisch, Bodo W.

    2005-01-01

    Auroral Kilometric Radiation (AKR) is a radio wave emission that has long been associated with auroral activity. AKR is normally observed in the frequency range from -60 - 600 kHz. Low frequency AKR (or LF-AKR) events are characterized as a rapid extension of AKR related emissions to 30 kHz or lower in frequency for typically much less than 10 minutes. LF-AKR emissions predominantly occur within a frequency range of 20 kHz - 30 kHz, but there are LF-AKR related emissions that reach to a frequency of 5 kHz. This study correlates all instances of LF-AKR events during the first four years of observations from the IMAGE spacecraft's Radio Plasma Imager (WI) instrument with auroral observations from the wideband imaging camera (WIC) onboard IMAGE. The correlation between LF-AKR occurrence and WIC auroral observations shows that in the 295 confirmed cases of LF-AKR emissions, bifurcation of the aurora is seen in 74% of the cases. The bifurcation is seen in the dusk and midnight sectors of the auroral oval, where AKR is believed to be generated. The polarization of these LF-AKR emissions has yet to be identified. Although LF-AKR may not be the only phenomena correlated with bifurcated auroral structures, bifurcation will occur in most instances when LF-AKR is observed. The LF-AKR emissions may be an indicator of specific auroral processes sometimes occurring during storm-time conditions in which field-aligned density cavities extend a distance of perhaps 5-6 RE tailward from the Earth for a period of 10 minutes or less.

  12. Hemispheric Assymeries in Auroral Precipitation

    NASA Astrophysics Data System (ADS)

    Mende, S. B.

    2014-12-01

    It is widely accepted that the space weather related electrodynamic forcing of the geospace environment acts through the high geomagnetic latitude regions. At high latitudes inter-hemispheric asymmetries are largely due to the differences in solar illumination, the direction of the solar wind and interplanetary magnetic field components and to a lesser extent, due to differences between the two hemispheric internal fields. So far most research regarding interhemispheric differences concentrated on learning about the basic magnetosphere-ionosphere coupling mechanisms. It has been well established that sunlit conditions affect the energy flux of auroral precipitation resulting from the reduction in the mean energy of the auroral electrons in the sunlit summer hemisphere. This can be explained by the partial shorting out of the particle accelerating fields by the sunlight induced conductivity. It has also been found that sunlit conditions reduce the particle fluxes and therefore the associated field aligned currents. Unless the precipitation-induced conductivities overwhelm the sunlit component of conductivity, this would imply that the magnetospheric current generator responds to the ionospheric load in a highly non-linear manner. Interhemispheric currents may also play an important role that has not been fully explored. Interhemispheric asymmetries in substorm morphology have been explored critically because conjugacy implies that substorms have a common source at equatorial latitudes. In some cases the lack of conjugacy of substorms could be explained by considering the magnitude and direction of the IMF.

  13. Observations of a gradual transition between Ps 6 activity with auroral torches and surgelike pulsations during strong geomagnetic disturbances

    SciTech Connect

    Steen, A.; Collis, P.N.; Evans, D.; Kremser, G.; Capelle, S.; Rees, D.; Tsurutani, B.T.

    1988-08-01

    A long-lasting large-amplitude pulsation event was observed on January 10, 1983, 0200--0600 UT (0411--0745 MLT) in the ionosphere and in the magnetosphere. In the ionosphere the characteristics of the pulsations changed from being Ps 6/auroral torches toward substorms and back to Ps 6 over the 4-hour period. At the geostationary orbit (6.6 Re) the corresponding characteristics were a modulation of the high-energy (greater than or equal to20 keV) particle intensity and plasma dropouts. Following the work by Rostoker and Samson (1984), we propose an interpretation of the event in which the pulsations are caused by the Kelvin-Helmholtz instability, during an interval of strong magnetospheric convection. The gradual transition between Ps 6 pulsations and substorm structures is interpreted as being different results of the Kelvin-Helmholtz instability, caused by different states of the magnetospheric convection. The proposed explanation forms the basis for a discussion on a simplified scheme of the substorm sequence. copyright American Geophysical Union 1988

  14. Investigating the auroral electrojets using Swarm

    NASA Astrophysics Data System (ADS)

    Smith, Ashley; Macmillan, Susan; Beggan, Ciaran; Whaler, Kathy

    2016-04-01

    The auroral electrojets are large horizontal currents that flow within the ionosphere in ovals around the polar regions. They are an important aspect of space weather and their position and intensity vary with solar wind conditions and geomagnetic activity. The electrojet positions are also governed by the Earth's main magnetic field. During more active periods, the auroral electrojets typically move equatorward and become more intense. This causes a range of effects on Earth and in space, including geomagnetically induced currents in power transmission networks, disturbance to radio communications and increased drag on satellites due to expansion of the atmosphere. They are also indicative of where the aurora are visible. Monitoring of the auroral electrojets in the pre-satellite era was limited to the network of ground-based magnetic observatories, from which the traditional AE activity indices are produced. These suffer in particular from the stations' poor distribution in position and so this motivates the use of satellite-based measurements. With polar low-Earth orbit satellites carrying magnetometers, all latitudes can be sampled with excellent resolution. This poster presents an investigation using Swarm's magnetometer data to detect the electrojets as the spacecraft move above them. We compare and contrast two approaches, one which uses vector data and the other which uses scalar data (Hamilton and Macmillan 2013, Vennerstrom and Moretto, 2013). Using ideas from both approaches we determine the oval positions and intensities from Swarm and earlier satellites. The variation in latitude and intensity with solar wind conditions, geomagnetic activity and secular variation of the main field is investigated. We aim to elucidate the relative importance of these factors. Hamilton, B. and Macmillan, S., 2013. Investigation of decadal scale changes in the auroral oval positions using Magsat and CHAMP data. Poster at IAGA 12th Scientific Assembly, 2013. http

  15. High Resolution Measurement of Auroral "Hiss" and "Roar"

    NASA Astrophysics Data System (ADS)

    Ye, S.; Labelle, J.; Weatherwax, A.

    2004-05-01

    In December 2002, a Versatile Electromagnetic Wave Receiver (VIEW) together with a new digitization system was deployed at South Pole station. The motivation was to measure three types of auroral radio emissions: Auroral Roar, a relatively narrowband (Δ f/f <0.1) emission near 2 and 3 times the F region ionospheric electron cyclotron frequency (fce); Auroral Hiss, a whistler mode wave emission with frequencies lower than 1MHz ; and Auroral medium frequency (MF) burst, broadband impulsive radio emissions observed at ground level during the breakup phase of auroral substorms. High resolution broad band structure of those three emissions are recorded automatically at South Pole, and are crucial to our understanding the mechanism and relations of auroral radio emissions. This experiment uses a 3x3 meter square magnetic dipole antenna, located 1.7 km away from the South Pole station. A pre-amplifier is buried right below the eastern pylon of the antenna, connected by a 1.7 km long co-axial cable to a LF-HF receiver in the station. The output of the receiver is fed into the Versatile Electromagnetic Wave Receiver (VIEW) and Windows system equipped with a digitization board. Software is written to digitize the selected signals at 1 or 2 MHz. This data acquisition system was designed so that researchers at Dartmouth College can review the data from South Pole weekly and save interesting parts according to instructions sent from Dartmouth. In the year of 2003, the experiment concentrated on the auroral roar frequency band. With 3 hours window per day, it captured more than 30 auroral roar events at South Pole station. The data show detailed structure of Auroral Roar, which is comprised of multiple narrow band features drifting in frequencies in a complicated pattern. ( LaBelle et al., 1995; Shepherd et al., 1998) Starting in 2004, the experiment is concentrating on the auroral hiss frequency band. This mode promises to caputure the first detailed structure of auroral hiss

  16. M-I coupling across the auroral oval at dusk and midnight: repetitive substorm activity driven by interplanetary coronal mass ejections (CMEs)

    NASA Astrophysics Data System (ADS)

    Sandholt, P. E.; Farrugia, C. J.; Denig, W. F.

    2014-04-01

    We study substorms from two perspectives, i.e., magnetosphere-ionosphere coupling across the auroral oval at dusk and at midnight magnetic local times. By this approach we monitor the activations/expansions of basic elements of the substorm current system (Bostrøm type I centered at midnight and Bostrøm type II maximizing at dawn and dusk) during the evolution of the substorm activity. Emphasis is placed on the R1 and R2 types of field-aligned current (FAC) coupling across the Harang reversal at dusk. We distinguish between two distinct activity levels in the substorm expansion phase, i.e., an initial transient phase and a persistent phase. These activities/phases are discussed in relation to polar cap convection which is continuously monitored by the polar cap north (PCN) index. The substorm activity we selected occurred during a long interval of continuously strong solar wind forcing at the interplanetary coronal mass ejection passage on 18 August 2003. The advantage of our scientific approach lies in the combination of (i) continuous ground observations of the ionospheric signatures within wide latitude ranges across the auroral oval at dusk and midnight by meridian chain magnetometer data, (ii) "snapshot" satellite (DMSP F13) observations of FAC/precipitation/ion drift profiles, and (iii) observations of current disruption/near-Earth magnetic field dipolarizations at geostationary altitude. Under the prevailing fortunate circumstances we are able to discriminate between the roles of the dayside and nightside sources of polar cap convection. For the nightside source we distinguish between the roles of inductive and potential electric fields in the two substages of the substorm expansion phase. According to our estimates the observed dipolarization rate (δ Bz/δt) and the inferred large spatial scales (in radial and azimuthal dimensions) of the dipolarization process in these strong substorm expansions may lead to 50-100 kV enhancements of the cross

  17. Potential structures and particle acceleration on auroral field lines

    NASA Astrophysics Data System (ADS)

    Gorney, D. J.

    Observations of plasmas and electric field activity within regions of auroral particle acceleration have verified the existence of electric fields with components parallel to the magnetic field over large altitude regions. Evidence is presented which indicates that small-ampliatude double layers along the auroral magnetic field lines may provide a mechanism for the maintenance of auroral ion potential. Evidence is also presented of downward-directed parallel electric fields along the magnetic field lines in the return current region. It is suggested that the downward electric fields may have significant effects on ion trajectories, and further theoretical investigation of the effects of downward parallel electric fields on ion conic formation is recommended.

  18. Theoretical and experimental studies relevant to interpretation of auroral emissions

    NASA Technical Reports Server (NTRS)

    Keffer, Charles E.

    1994-01-01

    This report describes the accomplishments of a program designed to develop the tools necessary to interpret auroral emissions measured from a space-based platform. The research was divided into two major areas. The first area was a laboratory study designed to improve our understanding of the space vehicle external environment and how it will affect the space-based measurement of auroral emissions. Facilities have been setup and measurements taken to simulate the gas phase environment around a space vehicle; the radiation environment encountered by an orbiting vehicle that passes through the Earth's radiation belts; and the thermal environment of a vehicle in Earth orbit. The second major area of study was a modeling program to develop the capability of using auroral images at various wavelengths to infer the total energy influx and characteristic energy of the incident auroral particles. An ab initio auroral calculation has been added to the extant ionospheric/thermospheric global modeling capabilities within our group. Once the addition of the code was complete, the combined model was used to compare the relative intensities and behavior of various emission sources (dayglow, aurora, etc.). Attached papers included are: 'Laboratory Facility for Simulation of Vehicle-Environment Interactions'; 'Workshop on the Induced Environment of Space Station Freedom'; 'Radiation Damage Effects in Far Ultraviolet Filters and Substrates'; 'Radiation Damage Effects in Far Ultraviolet Filters, Thin Films, and Substrates'; 'Use of FUV Auroral Emissions as Diagnostic Indicators'; and 'Determination of Ionospheric Conductivities from FUV Auroral Emissions'.

  19. Energy Budget of Alfven Wave Interactions with the Auroral Acceleration Region

    NASA Astrophysics Data System (ADS)

    Pilipenko, V.; Fedorov, E.; Engebretson, M. J.

    2003-12-01

    Recent Polar satellite observations of intense Alfven ULF bursts over auroral arcs prompted researchers to suggest that ULF wave activity does provide energy to the auroral arc intensification. However, to provide physical grounds for this suggestion, it is important to know possible bounds on the rate of the ULF wave energy transfer into electron acceleration. To estimate the power dissipated in the ionosphere and that transferred into electron acceleration, we consider the interaction of magnetospheric Alfven waves with the auroral ionosphere, comprising the auroral acceleration region (AAR). The AAR is characterized by a mirror resistance to the field-aligned upward current that can provide the potential drop and the acceleration of electrons. Analytical treatment of the interaction of Alfven waves with the combined magnetosphere-AAR-topside ionosphere-E-layer system has been made within the "thin" AAR approximation, which is valid for small-scale disturbances. The input of Alfven waves into the energy balance of the AAR depends critically on their transverse scale. Only waves with scales comparable to the Alfven transit scale, that is kperpendicular to λ A ˜= 1, will provide energy into electron acceleration. This process is expected to be more effective above a conductive ionosphere. These theoretical predictions could be verified with the multi-satellite measurements in the Cluster-2 mission.

  20. Solar cycle and diurnal dependence of auroral structures

    NASA Astrophysics Data System (ADS)

    Partamies, N.; Whiter, D.; Syrjäsuo, M.; Kauristie, K.

    2014-10-01

    In order to facilitate usage of optical data in space climate studies, we have developed an automated algorithm to quantify the complexity of auroral structures as they appear in ground-based all-sky images. The image analysis is based on a computationally determined "arciness" value, which describes how arc like the auroral structures in the image are. With this new automatic method we have analyzed the type of aurora in about 1 million images of green aurora (λ = 557.7nm) captured at five camera stations in Finnish and Swedish Lapland in 1996-2007. We found that highly arc like structures can be observed in any time sector and their portion of the auroral structures varies much less than the fraction of more complex forms. The diurnal distribution of arciness is in agreement with an earlier study with high arc occurrence rate in the evening hours and steadily decreasing toward the late morning hours. The evolution of less arc-like auroral structures is more dependent on the level of geomagnetic activity and solar cycle than the occurrence of arcs. The median arciness is higher during the years close to the solar minimum than during the rest of the solar cycle. Unlike earlier proposed, the occurrence rate of both arcs and more complex auroral structures increases toward the solar maximum and decreases toward the solar minimum. The cyclic behavior of auroral structures seen in our data is much more systematic and clear than previously reported visual studies suggest. The continuous arciness index describing the complexity of auroral structures can improve our understanding on auroral morphology beyond the few commonly accepted structure classes, such as arcs, patches, and omega bands. Arciness can further be used to study the relationship of auroral structures at different complexity levels and magnetospheric dynamics.

  1. Research activities on Antarctic middle atmosphere by JARE 25th team

    NASA Technical Reports Server (NTRS)

    Hirasawa, T.; Eiwasaka, Y. AFTANAKA, M. agfujii, r.0 typ; Eiwasaka, Y. AFTANAKA, M. agfujii, r.0 typ

    1985-01-01

    The Antarctic Middle Atmosphere (AMA)-Japan research project was set about by the JARE (Japan Antarctic Research Expedition) 23rd team in 1982, and since then the JARE-24th and JARE-25th teams have been continuing reseach on the Antarctic Middle Atmosphere. Results gained by JARE-25th team members who are now working at Syowa Station (69.99 deg S, 39.35 deg E), Antarctica are presented. In their activities satellite measurements (Exos-C) and rocket soundings are used. Three rockets of the S310 type were launched at Syowa Station (Geomagnetic Latitude = 69.9 deg S) for the purpose of directly observing the electron density, ionospheric temperature, auroral patterns and luminosity in situ. Vertical profiles of electron density and auroral emission 4278A measured by three rockets are compared.

  2. Morphology of auroral zone radio wave scintillation

    SciTech Connect

    Rino, C.L.; Matthews, S.J.

    1980-08-01

    This paper describes the morphology of midnight sector and morning sector auroral zone scintillation observations made over a two-year period using the Wideband satelite, which is in a sun-synchronous, low-altitude orbit. No definitive seasonal variation was found. The nighttime data showed the highest scintillation ocurrence levels, but significant amounts of morning scintillation were observed. For the most part the scintillation activity followed the general pattern of local magnetic activity. The most prominent feature in the nightime data is a localized amplitude and phase scintillation enhancement at the point where the propagation vector lies within an L shell. A geometrical effect due to a dynamic slab of sheetlike structures in the F region is hypothesized as the source of his enhancement. The data have been sorted by magnetic activity, proximity to local midnight, and season. The general features of the data are in agreement with the accepted morphology of auroral zone scintillation.

  3. DISCOVERY OF A DARK AURORAL OVAL ON SATURN

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The ultraviolet image was obtained by the NASA/ESA Hubble Space Telescope with the European Faint Object Camera (FOC) on June 1992. It represents the sunlight reflected by the planet in the near UV (220 nm). * The image reveals a dark oval encircling the north magnetic pole of Saturn. This auroral oval is the first ever observed for Saturn, and its darkness is unique in the solar system (L. Ben-Jaffel, V. Leers, B. Sandel, Science, Vol. 269, p. 951, August 18, 1995). The structure represents an excess of absorption of the sunlight at 220 nm by atmospheric particles that are the product of the auroral activity itself. The large tilt of the northern pole of Saturn at the time of observation, and the almost perfect symmetry of the planet's magnetic field, made this observation unique as even the far side of the dark oval across the pole is visible! * Auroral activity is usually characterized by light emitted around the poles. The dark oval observed for Saturn is a STUNNING VISUAL PROOF that transport of energy and charged particles from the magnetosphere to the atmosphere of the planet at high latitudes induces an auroral activity that not only produces auroral LIGHT but also UV-DARK material near the poles: auroral electrons are probably initiating hydrocarbon polymer formation in these regions. Credits: L. Ben Jaffel, Institut d'Astrophysique de Paris-CNRS, France, B. Sandel (Univ. of Arizona), NASA/ESA, and Science (magazine).

  4. GAIA - A Virtual Auroral Observatory

    NASA Astrophysics Data System (ADS)

    Donovan, E.; Spanswick, E.; Syrj M; Marple, S.; Jackel, B.; Kauristie, K.; Honary, F.; Mende, S.; Weatherwax, A.; Moen, J.; Sandahl, I.

    2005-12-01

    Advancements in computer, communications, and instrument technologies have spawned an explosion of activity in ground-based geospace observations. There is increasing interest in the development of virtual observatories as we approach the International Polar and Heliosphysical Years and the electronic Geophysical Year, and are faced with burgeoning data sets from arrays of different instrument types the world over. We are developing a virtual observatory for dealing with data from geospace optical and riometer systems. While these two classes of instruments are very different in their observational technique, they are close relatives in what they observe, which is primarily auroral precipitation. The GAIA (Global Auroral Imaging Access) Project is a network-based set of tools for browsing summary data from All-Sky Imagers (ASIs), Meridian Scanning Photometers (MSPs), and riometers worldwide, and that provides indexes for direct access to data at PI institutes. This program is the virtual observatory component of the IPY Auroral Optical Network (AON) and GLORIA (Global Riometer Imaging Array) projects, and falls under the ICESTAR IPY grouping. As well, GAIA is being developed so as to be fully consistent with the data policies described in the `Declaration of the eGY'. We demonstrate the GAIA concept with ASI data from Canada and Finland, MSP data from Canada, and riometer data from Canada and Scandinavia. We explore the requirements that such a system must meet in order to be successful, which include ease of use, credit to data providers, ability for data providers to monitor usage, and reliance on software rather than hardware. The latter is consistent with our concept of a summary data set consisting of keograms, time series, and thumbnail images, a fully peer to peer data access system, and a relational data base that allows for easy grouping of and linkages between data. We describe how we are ensuring that GAIA is compatible with larger efforts such as SPIDR

  5. An auroral breakup mechanism

    NASA Technical Reports Server (NTRS)

    Maggs, J. E.

    1973-01-01

    A purely growing electrostatic drift instability driven by the electron temperature gradient at the inner edge of the plasma sheet can grow for large enough values of the temperature gradient. The parallel electric field associated with the instability is localized near the magnetic equator. The growth of the drift instability leads to enhanced whistler noise and increased electron pitch angle diffusion. If the current limit is exceeded in the ionosphere while the parallel electric field of the drift instability exists along the field line, rapid electron precipitation (the auroral breakup) can result.

  6. Landau damping of auroral hiss

    NASA Technical Reports Server (NTRS)

    Morgan, D. D.; Gurnett, D. A.; Menietti, J. D.; Winningham, J. D.; Burch, J. L.

    1994-01-01

    Auroral hiss is observed to propagate over distances comparable to an Earth radius from its source in the auroral oval. The role of Landau damping is investigated for upward propagating auroral hiss. By using a ray tracing code and a simplified model of the distribution function, the effect of Landau damping is calculated for auroral hiss propagation through the environment around the auroral oval. Landau damping is found to be the likely mechanism for explaining some of the one-sided auroral hiss funnels observed by Dynamics Explorer 1. It is also found that Landau damping puts a lower limit on the wavelength of auroral hiss. Poleward of the auroral oval, Landau damping is found in a typical case to limit omega/k(sub parallel) to values of 3.4 x 10(exp 4) km/s or greater, corresponding to resonance energies of 3.2 keV or greater and wavelengths of 2 km or greater. For equatorward propagation, omega/k(sub parallel) is limited to values greater than 6.8 x 10(exp 4) km/s, corresponding to resonance energies greater than 13 keV and wavelengths greater than 3 km. Independent estimates based on measured ratios of the magnetic to electric field intensity also show that omega/k(sub parallel) corresponds to resonance energies greater than 1 keV and wavelengths greater than 1 km. These results lead to the difficulty that upgoing electron beams sufficiently energetic to directly generate auroral hiss of the inferred wavelength are not usually observed. A partial transmission mechanism utilizing density discontinuities oblique to the magnetic field is proposed for converting auroral hiss to wavelengths long enough to avoid damping of the wave over long distances. Numerous reflections of the wave in an upwardly flared density cavity could convert waves to significantly increased wavelengths and resonance velocities.

  7. Landau damping of auroral hiss

    SciTech Connect

    Morgan, D.D.; Gurnett, D.A.; Menietti, J.D.; Winningham, J.D.; Burch, J.L.

    1994-02-01

    Auroral hiss is observed to propagate over distances comparable to an Earth radius from its source in the auroral oval. The role of Landau damping is investigated for upward propagating auroral hiss. By using a ray tracing code and a simplified model of the distribution function, the effect of Landau damping is calculated for auroral hiss propagation through the environment around the auroral oval. Landau damping is found to be the likely mechanism for explaining some of the one-sided auroral hiss funnels observed by Dynamics Explorer 1. It is also found that Landau damping puts a lower limit on the wavelength of auroral hiss. Poleward of the auroral oval, Landau damping is found in a typical case to limit {omega}/k{parallel} to values of 3.4 x 10{sup 4} km/s or greater, corresponding to resonance energies of 3.2 keV or greater and wavelengths of 2 km or greater. For equatorward propagation, {omega}/k{parallel} is limited to values greater than 6.8 x 10{sup 4} km/s, corresponding to resonance energies greater than 13 keV and wavelengths greater than 3 km. Independent estimates based on measured ratios of the magnetic to electric field intensity also show that {omega}/k{parallel} corresponds to resonance energies greater than 1 keV and wavelengths greater than 1 km. These results lead to the difficulty that upgoing electron beams sufficiently energetic to directly generate auroral hiss of the inferred wavelength are not usually observed. A partial transmission mechanism utilizing density discontinuities oblique to the magnetic field is proposed for converting auroral hiss to wavelengths long enough to avoid damping of the wave over long distances. Numerous reflections of the wave in an upwardly flared density cavity could convert waves to significantly increased wavelengths and resonance velocities. 36 refs., 12 figs., 4 tabs.

  8. Cross-field current instability for auroral bead formation in breakup arcs

    NASA Astrophysics Data System (ADS)

    Lui, A. T. Y.

    2016-06-01

    The physical process responsible for the onset of substorm expansion is still unresolved in spite of decades of research on the topic. Detailed properties of the spatially periodic auroral beads on prebreakup auroral arcs that initiate substorm expansion onset are now available. These auroral bead properties impose severe observational constraints on the onset process. In this work, theoretical predictions of the cross-field current instability are evaluated in terms of these constraints. The growth rates and wavelengths associated with auroral beads in several previously published events are reproduced by the cross-field current instability, implying that the instability can indeed account for the characteristics of auroral beads that eventually lead to substorm onset. The present results differ from the conclusion reached by a previous analysis that the shear flow ballooning instability can account for the growth and spatial scales of auroral beads better than the cross-field current instability.

  9. Ionospheric heating, upwelling, and depletions in auroral current systems

    NASA Astrophysics Data System (ADS)

    Zettergren, M. D.; Semeter, J. L.

    2010-12-01

    This research investigates aspects of ionospheric dynamics relevant to magnetosphere-ionosphere coupling in auroral arc current systems. Auroral electric fields and particle precipitation deposit energy in the ionosphere, often resulting in enhanced ion or electron temperatures. This heating has a wide variety of consequences for the ionosphere. High ion temperatures alter chemical balance in the lower F-region, resulting in conversion to a molecular ion plasma, faster recombination, and plasma depletions. Pressure enhancements resulting from both ion and electron heating are capable of generating intense ion upflows. Ion upflow and depletion processes redistribute and structure the auroral plasma in ways that are likely of consequence to wave coupling of the magnetosphere and ionosphere. These implications are examined through the use of a fluid-kinetic model of the auroral ionosphere and new incoherent scatter radar data analysis techniques. Results indicate that enhanced recombination of molecular ions in auroral downward current regions may work in concert with well-known electrodynamic depletion processes, in the F-region ionosphere. Furthermore, ionospheric upflows in auroral upward and downward current regions may be quite different in terms of intensity and types of upflowing ions.

  10. Auroral-E observations: The first year's data

    NASA Astrophysics Data System (ADS)

    Rose, R. B.; Hunsucker, R. D.

    1993-02-01

    Personnel at the Naval Command, Control and Ocean Surveillance Center, RDT and E Division, and RP Consultants conducted a year-long study to measure and characterize auroral-E propagation. Personnel installed a 100-watt transmitter at the Arctic Submarine Laboratory at Cape Prince of Wales (67 N, 168 W) and a receiver at RP Consultants' facilities 900 kilometers away. Both sites used simple dipole antennas. The transmitter sent a slow morse R on a frequency of 25.545 megahertz (MHz). Only a very dense patch of ionization, typical of sporadic-E or auroral-E with foEs greater than 5 MHz, would sustain a sky-wave signal over this path. The solar sunspot number declined from 175 to less than 100 during the test period. Personnel recorded over 1400 auroral sporadic-mode observations whose durations spanned 1 minute to several hours. A strong diurnal dependence was noted. This document presents an initial characterization of auroral-E occurrences, noting time of day, season, and magnetic activity. It discusses some implications of auroral-E occurrence intensity. The data are also discussed with respect to the development of a new auroral-E expert system model.

  11. Auroral interactions with ISSA

    NASA Technical Reports Server (NTRS)

    Purvis, Carolyn K.; Snyder, David B.; Jongeward, Gary A.

    1994-01-01

    Due to its high inclination orbit, International Space Station Alpha (ISSA) will occasionally experience surface charging by the high energy electrons of the auroral environment. This study looks at the frequency of these occurrences and recapitulates a charging model. ISSA should expect about 80 auoral encounters annually. If the plasma contactor is not run continuously, the vehicle may charge several hundred volts. Charge storage on standard space station coatings should not be a problem, but care must be taken that materials are not introduced inadvertently that cannot bleed off accumulated charge in a reasonable time. A conductivity requirement may be used to ensure surface materials do not charge to high voltages, or store charge for long periods of time.

  12. Auroral bright spots on the dayside oval

    SciTech Connect

    Lui, A.T.Y. ); Venkatesan, D.; Murphree, J.S. )

    1989-05-01

    Global auroral images from the ultraviolet imager on the Viking spacecraft are used to investigate spatially periodic bright spots on the dayside auroral oval that resemble beads on a string. The newly achieved temporal resolution of 1 min. or less in monitoring worldwide auroral distributions by the Viking imager contributes significant to the capability of observing this phenomenon. It is found that these are frequently seen in the 1,400-1,600 MLT sector. The series of bright spots are not, however, limited to this unique local time sector, since they are seen to extend into the prenoon sector on some occasions. They occur often during substorm intervals but are also seen unaccompanied by substorm activities in the nightside. There is neither a consistent north-south nor east-west direction of motion for all the dayside bright spots observed so far. The observation of the time scales for the transient intensifications of bright spots and the lack of consistent directions of their motion are consistent with the characteristics expected from the suggestion that these bright spots are related to the Kelvin-Helmholtz instability occurring within the magnetosphere.

  13. FAST/Polar Conjunction Study of Field-Aligned Auroral Acceleration and Corresponding Magnetotail Drivers

    NASA Technical Reports Server (NTRS)

    Schriver, D.; Ashour-Abdalla, M.; Strangeway, R. J.; Richard, R. L.; Klezting, C.; Dotan, Y.; Wygant, J.

    2003-01-01

    The discrete aurora results when energized electrons bombard the Earth's atmosphere at high latitudes. This paper examines the physical processes that can cause field-aligned acceleration of plasma particles in the auroral region. A data and theoretical study has been carried out to examine the acceleration mechanisms that operate in the auroral zone and to identi@ the magnetospheric drivers of these acceleration mechanisms. The observations used in the study were collected by the Fast Auroral Snapshot (FAST) and Polar satellites when the two satellites were in approximate magnetic conjunction in the auroral region. During these events FAST was in the middle of the auroral zone and Polar was above the auroral zone in the near-Earth plasma sheet. Polar data were used to determine the conditions in the magnetotail at the time field-aligned acceleration was measured by FAST in the auroral zone. For each of the magnetotail drivers identified in the data study, the physics of field-aligned acceleration in the auroral region was examined using existing theoretical efforts and/or a long-system particle in cell simulation to model the magnetically connected region between the two satellites. Results from the study indicate that there are three main drivers of auroral acceleration: (1) field-aligned currents that lead to quasistatic parallel potential drops (parallel electric fields), (2) earthward flow of high-energy plasma beams from the magnetotail into the auroral zone that lead to quasistatic parallel potential drops, and (3) large-amplitude Alfven waves that propagate into the auroral region from the magnetotail. The events examined thus far confm the previously established invariant latitudinal dependence of the drivers and show a strong dependence on magnetic activity. Alfven waves tend to occur primarily at the poleward edge of the auroral region during more magnetically active times and are correlated with intense electron precipitation. At lower latitudes away

  14. DMSP Auroral Charging at Solar Cycle 24 Maximum

    NASA Technical Reports Server (NTRS)

    Chandler, Michael; Parker, Linda Neergaard; Minow, Joseph I.

    2013-01-01

    It has been well established that polar orbiting satellites can experience mild to severe auroral charging levels (on the order of a few hundred volts to few kilovolts negative frame potentials) during solar minimum conditions (Frooninckx and Sojka, 1992; Anderson and Koons, 1996; Anderson, 2012). These same studies have shown a strong reduction in charging during the rising and declining phases of the past few solar cycles with a nearly complete suppression of auroral charging at solar maximum. Recently, we have observed examples of high level charging during the recent approach to Solar Cycle 24 solar maximum conditions not unlike those reported by Frooninckx and Sojka (1992). These observations demonstrate that spacecraft operations during solar maximum cannot be considered safe from auroral charging when solar activity is low. We present a survey of auroral charging events experienced by the Defense Meteorological Satellite Program (DMSP) F16 satellite during Solar Cycle 24 maximum conditions. We summarize the auroral energetic particle environment and the conditions necessary for charging to occur in this environment, we describe how the lower than normal solar activity levels for Solar Cycle 24 maximum conditions are conducive to charging in polar orbits, and we show examples of the more extreme charging events, sometimes exceeding 1 kV, during this time period.

  15. DMSP Auroral Charging at Solar Cycle 24 Maximum

    NASA Technical Reports Server (NTRS)

    Chandler, M.; Parker, L. Neergaard; Minow, J. I.

    2013-01-01

    It has been well established that polar orbiting satellites can experience mild to severe auroral charging levels (on the order of a few hundred volts to few kilovolts negative frame potentials) during solar minimum conditions. These same studies have shown a strong reduction in charging during the rising and declining phases of the past few solar cycles with a nearly complete suppression of auroral charging at solar maximum. Recently, we have observed examples of high level charging during the recent approach to Solar Cycle 24 solar maximum conditions not unlike those reported by Frooninckx and Sojka. These observations demonstrate that spacecraft operations during solar maximum cannot be considered safe from auroral charging when solar activity is low. We present a survey of auroral charging events experienced by the Defense Meteorological Satellite Program (DMSP) F16 satellite during Solar Cycle 24 maximum conditions. We summarize the auroral energetic particle environment and the conditions necessary for charging to occur in this environment, we describe how the lower than normal solar activity levels for Solar Cycle 24 maximum conditions are conducive to charging in polar orbits, and we show examples of the more extreme charging events, sometimes exceeding 1 kV, during this time period.

  16. Ducted auroral kilometric radiation

    NASA Technical Reports Server (NTRS)

    Calvert, W.

    1982-01-01

    Certain discrete, intense wave signals attributed to auroral kilometric radiation (AKR) were observed with ISEE-l while it was within the plasmaspheric shadow zone for direct propagation. It is believed that wave ducting by thin depletions of the plasma density aligned with the magnetic field accounts for such signals, and that their discrete nature is caused by the satellite intercepting individual ducts. These ducts, which were also observed as coincident decreases of the upper hybrid resonance frequency, appeared to be twenty-percent depletions roughly one hundred kilometers across. The AKR, which is emitted approximately perpendicular to the magnetic field, apparently entered these ducts equatorward of the source after the waves had been refracted parallel to the duct axis. A diffuse background was also observed which is consistent with the leakage from similar ducts at lower L-values. These observations establish the existence of ducted AKR, its signature on the satellite wave spectrograms, and new evidence for depletion ducts within the plasmasphere.

  17. Characteristics of Extreme Auroral Charging Events

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Willis, Emily; Parker, Linda Neergaard

    2014-01-01

    Today’s presentation describes preliminary results from a study of extreme auroral charging in low Earth orbit. Goal of study is to document characteristics of auroral charging events of importance to spacecraft design, operations, and anomaly investigations.

  18. Comparison of ionospheric scintillation statistics from the North Atlantic and Alaskan sectors of the auroral oval using the wideband satellite. Environmental research papers

    SciTech Connect

    Basu, S.; Basu, S.; Livingston, R.C.; Whitney, H.E.; MacKenzie, E.

    1981-09-15

    Phase and amplitude scintillation measurements made at 138 MHz at two widely separated auroral stations, Goose Bay, Labrador, and Anchorage, Alaska, are presented. The phase coherent transmissions obtained from the sun-synchronous Wideband satellite were used for this purpose. The data were obtained for part of the year 1979 during a high sunspot epoch and was terminated by the failure of the Wideband satellite in August, 1979. The primary objective of the report is the presentation of scintillation statistics in a manner required for communications system planning. The morphology at the two stations was found to be significantly different with more nighttime scintillations observed at Goose Bay, while many more daytime scintillations were observed at Anchorage during the same season. The report establishes the existence of L-shell aligned sheets in the daytime in addition to the well-established similar geometry at night. The existence of sheetlike irregularities during the daytime well-equatorward of the auroral oval is significant both from modeling and physical standpoints.

  19. Electron and Proton Auroral Dynamics

    NASA Technical Reports Server (NTRS)

    Mende, S. B.; Frey, H. U.; Gerard, J. C.; Hubert, B.; Fuselier, S.; Spann, J. F., Jr.; Gladstone, R.; Burch, J. L.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Data from the Wide-band Imaging Camera (WIC) sensitive to far ultraviolet auroras and from the Spectrographic Imager (SI) channel SI12, sensitive to proton precipitation induced Lyman alpha were analyzed during a high altitude orbit segment of the IMAGE spacecraft. This segment began during the expansive phase of a substorm. The aurora changed into a double oval configuration, consisting of a set of discrete pole-ward forms and a separate diffuse auroral oval equatorwards, Although IMF Bz was strongly southward considerable activity could be seen poleward of the discrete auroras in the region that was considered to be the polar cap. The SI12 Doppler shifted Lyman alpha signature of precipitating protons show that the proton aurora is on the equatorward side of the diffuse aurora. In the following several hours the IMF Bz field changed signed. Although the general character of the proton and electron aurora did not change, the dayside aurora moved equatorward when the Bz was negative and more bright aurora was seen in the central polar cap during periods of positive Bz.

  20. The Auroral Particles experiment

    NASA Technical Reports Server (NTRS)

    1981-01-01

    An instrument for the detection of particles in the energy range of 0.1 ev to 80 Kev was designed, built, tested, calibrated, and flown onboard the spacecraft ATS-6. Data from this instrument generated the following research: intensive studies of the plasma in the vicinity of the spacecraft; global variations of plasmas; correlative studies using either other spacecraft or ground based measurements; and studies of spacecraft interactions with ambient plasmas including charging, local electric fields due to differential charging, and active control of spacecraft potential. Results from this research are presented.

  1. The Consequences of Alfven Waves and Parallel Potential Drops in the Auroral Zone

    NASA Technical Reports Server (NTRS)

    Schriver, David

    2003-01-01

    The goal of this research is to examine the causes of field-aligned plasma acceleration in the auroral zone using satellite data and numerical simulations. A primary question to be addressed is what causes the field-aligned acceleration of electrons (leading to precipitation) and ions (leading to upwelling ions) in the auroral zone. Data from the Fast Auroral SnapshoT (FAST) and Polar satellites is used when the two satellites are in approximate magnetic conjunction and are in the auroral region. FAST is at relatively low altitudes and samples plasma in the midst of the auroral acceleration region while Polar is at much higher altitudes and can measure plasmas and waves propagating towards the Earth. Polar can determine the sources of energy streaming earthward from the magnetotail, either in the form of field-aligned currents, electromagnetic waves or kinetic particle energy, that ultimately leads to the acceleration of plasma in the auroral zone. After identifying and examining several events, numerical simulations are run that bridges the spatial region between the two satellites. The code is a one-dimensional, long system length particle in cell simulation that has been developed to model the auroral region. A main goal of this research project is to include Alfven waves in the simulation to examine how these waves can accelerate plasma in the auroral zone.

  2. ISIS-2 satellite imagery and auroral morphology

    NASA Technical Reports Server (NTRS)

    Anger, C. D.; Murphree, J. S.

    1976-01-01

    Auroral morphology is emphasized over auroral dynamics in a paper describing conspicuous auroral features picked up by the ISIS-2 scanning photometer. Results of improved programs designed to transform the data into a corrected geomagnetic coordinate frame and generate latitude profiles of auroral intensities at different magnetic local times are reported. The diffuse aurora and its relation to the morphology of discrete aurorae is given special attention.

  3. An empirical model of FUV auroral intensity

    NASA Astrophysics Data System (ADS)

    Tur, Moshe; Oznovich, Israel

    1992-02-01

    A statistical model of auroral intensity as a function of magnetic activity was created. The model was derived from several hundred 1356A images of the aurora borealis obtained by Polar BEAR at solar minimum. Intensities were averaged in 35 divisions of CGL (from 55 deg to 90 deg, each division 1 deg long), 48 divisions of MLT (each division half an hour wide), and 5 divisions of magnetic activity (K(sub p) = 0-4). The peak oval intensity is located near midnight for all K sub p values but 0. Two secondary maxima in the average 1356A intensity are found in the dayside part of the oval: one in morning and one in the afternoon. The peak nightside, morning, and afternoon intensity increase monotonically with magnetic activity. The latitude of peak emission increases with K(sub p) at night and decreases in the dayside. The latitudinal extent of the oval is largest at or near the intensity peaks and increases with magnetic activity. The model of average auroral intensity was related to a statistical model of electron precipitation into the high-latitude ionosphere. The precipitation data leading to auroral emissions show a power law relationship between the energy flux and the average energy of the precipitation electrons. The average electron energy associated with the peak 1356A oval emission is 0.8-1.7 keV at night, predominantly 0.3-0.7 keV in the morning, and predominantly 0.2-0.5 keV in the afternoon. Polar cap emissions are associated with very cold electrons (0.3-0.4 keV).

  4. Constant auroral forms during regular pulsations

    NASA Astrophysics Data System (ADS)

    Roldugin, V. K.; Roldugin, A. V.

    2016-01-01

    A case is described in which complex auroral forms varied slightly at Lovozero Observatory over the course of more than an hour in the morning hours during the auroral recovery phase. Pc3 and Pc5 auroral and geomagnetic pulsations were observed during the event. The phenomenon is compared with recurrent pulsating auroras, which are described in the literature.

  5. HF sounding of the auroral magnetosphere

    NASA Astrophysics Data System (ADS)

    Gurevich, A. V.; Babichenko, A. M.; Karashtin, A. N.; Rapoport, V. O.

    1992-06-01

    Results are presented from incoherent scatter radar measurements in the magnetosphere, using the Radiophysical Research Institute 'Sura' heating facility operated in the frequency range 4.5-9 MHz. The first magnetosphere sounding experiments were carried out on February 21, 1989; a frequency of 9.310 MHz was used for the sounding, while the effective radiated power was about 30 MW. The results of analyses of the scattered signal spectra showed that, in the auroral region of the polar magnetosphere, ion acoustic oscillations are excited and that the HF sounding technique used in this study was an effective method for magnetosphere sounding.

  6. Automatic georeferencing of astronaut auroral photography

    NASA Astrophysics Data System (ADS)

    Riechert, Maik; Walsh, Andrew P.; Gerst, Alexander; Taylor, Matthew G. G. T.

    2016-07-01

    Astronauts on board the International Space Station (ISS) have taken thousands of high-resolution colour photographs of the aurora, which could be made useful for research if their pointing information could be reconstructed. We describe a method to do this using the star field in the images, and how the reconstructed pointing can then be used to georeference the images to a similar level of accuracy in existing all-sky camera images. We have used this method to make georeferenced auroral images taken from the ISS available and here describe the resulting data set, processing software, and how to access them.

  7. High Resolution Measurement of LF Auroral Hiss at South Pole

    NASA Astrophysics Data System (ADS)

    Ye, S.; Labelle, J.

    2005-05-01

    In December 2002, a Versatile Electromagnetic Wave Receiver (VIEW) and a new digitization system were deployed at South Pole station(-74° magnetic latitude). The motivation was to measure three types of auroral radio emissions: Auroral Roar, a relatively narrowband (δf/f<0.1) emission near 2 and 3 times the F region ionospheric electron cyclotron frequency (fce); Auroral Hiss, a whistler mode wave emission with frequencies lower than 1MHz; and Auroral medium frequency (MF) burst, broadband impulsive radio emissions observed at ground level during the breakup phase of auroral substorms. High resolution broad band structure of those three emissions are recorded automatically at South Pole, and are crucial to our understanding the mechanism and relations of auroral radio emissions. This experiment uses a 3×3 meter square magnetic dipole antenna, located 1.7 km away from the South Pole station. A pre-amplifier is buried right below the eastern pylon of the antenna, connected by a 1.7 km long co-axial cable to a LF-HF receiver in the station. The output of the receiver is fed into the Versatile Electromagnetic Wave Receiver (VIEW) and Windows system equipped with a digitization board. Customed software was used to digitize the selected signals at 1-2 MHz. This data acquisition system was designed so that researchers at Dartmouth College can review the data from South Pole weekly and save interesting parts according to instructions sent from Dartmouth. In the year of 2004(from Jan through September), the experiment concentrated on the auroral hiss frequency band, covering either 0-500 kHz or 0-1000 kHz. With 3-6 hours window per day, VIEW captured more than 30 GBytes data of auroral hiss waveforms. Many experiments report wave forms of VLF auroral hiss at f < 30 kHz. We focused on waveforms of LF auroral hiss, typically at 100-300 kHz. At these frequencies, the hiss shows striking fine structure. We classified our LF hiss events into three different types: standard

  8. Auroral oval as a beautiful but outdated paradigm

    NASA Astrophysics Data System (ADS)

    Lazutin, Leonid

    2015-03-01

    Auroral oval as an important region of the polar ionosphere presents in a considerable number of a studies of the disturbed magnetosphere. It seems that all about oval is known to all researchers. But there are evidences in a publications that misunderstanding exists and that it is a time for a review on this subject. Most of papers describing auroral position and dynamics were published years ago and became a rarity. We will tell on the history of aurora's distribution before the oval discovery, how the oval was discovered and how it changed our point of view on magnetosphere processes. We will tell also how the oval paradigm grows and haw with time it became non-productive (at our point of view) for a studies of magnetosphere structure and disturbances. Finally we will indicate the position of the aural zone and auroral magnetosphere among the main domains of the magnetosphere.

  9. Rocket study of auroral processes

    NASA Technical Reports Server (NTRS)

    Arnoldy, R. L.

    1981-01-01

    Abstracts are presented of previously published reports analyzing data from three Echo 3 rocket flights. Particle experiments designed for the Terrier-Malmute flight, the Echo 5 flight, and the Norwegian Corbier Ferdinand 50 flight are described and their flight performance evaluated. Theoretical studies on auroral particle precipitation are reviewed according to observations made in three regions of space: (1) the region accessible to rockets and low altitude satellites (few hundred to a few thousand kilometers); (2) the region extending from 4000 to 8000 km (S3-3 satellite range); and (3) near the equatorial plane (geosynchronous satellite measurements). Questions raised about auroral arc formation are considered.

  10. V and V Efforts of Auroral Precipitation Models: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Zheng, Yihua; Kuznetsova, Masha; Rastaetter, Lutz; Hesse, Michael

    2011-01-01

    Auroral precipitation models have been valuable both in terms of space weather applications and space science research. Yet very limited testing has been performed regarding model performance. A variety of auroral models are available, including empirical models that are parameterized by geomagnetic indices or upstream solar wind conditions, now casting models that are based on satellite observations, or those derived from physics-based, coupled global models. In this presentation, we will show our preliminary results regarding V&V efforts of some of the models.

  11. Electrodynamic response of the middle atmosphere to auroral pulsations

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.; Croskey, C. L.; Hale, L. C.; Mitchell, J. D.; Barcus, J. R.

    1990-01-01

    The MAC/EPSILON observational campaign encompassed the use of two Nike Orion rocket payloads which studied the effects of auroral energetics on the middle atmosphere. While one payload was launched during the recovery phase of a moderate magnetic substorm, during fairly stable auroral conditions, the other was launched during highly active postbreakup conditions during which Pc5 pulsations were in progress. The energetic radiation of the first event was composed almost entirely of relativistic electrons below 200 keV, while that of the second was dominated by much softer electrons whose high X-ray fluxes exceeded the cosmic ray background as an ionizing source down to below 30 km.

  12. Jupiter's Various Auroral Emission Enhancements Observed by Hisaki/EXCEED

    NASA Astrophysics Data System (ADS)

    Tao, Chihiro

    2016-07-01

    Onboard a JAXA Earth-orbiting platform, the planetary telescope Hisaki monitors extreme ultraviolet emissions from Jovian aurora and Io plasma torus continuously. Hisaki succeeded to detect sporadic, large auroral power enhancements displaying both short- (<1 planetary rotation) and long-term (>a few rotations) variations and their modulations by Io's volcanic activity over several weeks. The spectral information taken by Hisaki enables us to investigate (1) the time variation of the auroral electron precipitating fluxes during these emission enhancements, (2) the occurrence statistics of polar-dominant events, and (3) the associated magnetospheric dynamics for these emission enhancement events using Knight's aurora acceleration theory. Expected collaborative observations with Juno will be discussed.

  13. Planning and Conducting Research Activities.

    ERIC Educational Resources Information Center

    Christiansen, Richard L.

    1983-01-01

    Some directions and influences on dental research activities in the near future are discussed. Current challenges include international competition, fellowships, and equipment. Potential research activity includes preventive medicine, epidemiology, chronic illness, the elderly, bioengineering, materials research, nutrition, soft tissue research,…

  14. Current Closure in the Auroral Ionosphere: Results from the Auroral Current and Electrodynamics Structure Rocket Mission

    NASA Technical Reports Server (NTRS)

    Kaeppler, S. R.; Kletzing, C. A.; Bounds, S. R.; Gjerloev, J. W.; Anderson, B. J.; Korth, H.; LaBelle, J. W.; Dombrowski, M. P.; Lessard, M.; Pfaff, R. F.; Rowland, D. E.; Jones, S.; Heinselman, C. J.

    2011-01-01

    The Auroral Current and Electrodynamics Structure (ACES) mission consisted of two sounding rockets launched nearly simultaneously from Poker Flat Research Range, AK on January 29, 2009 into a dynamic multiple-arc aurora. The ACES rocket mission was designed to observe electrodynamic and plasma parameters above and within the current closure region of the auroral ionosphere. Two well instrumented payloads were flown along very similar magnetic field footprints, at different altitudes, with small temporal separation between both payloads. The higher altitude payload (apogee 360 km), obtained in-situ measurements of electrodynamic and plasma parameters above the current closure region to determine the input signature. The low altitude payload (apogee 130 km), made similar observations within the current closure region. Results are presented comparing observations of the electric fields, magnetic components, and the differential electron energy flux at magnetic footpoints common to both payloads. In situ data is compared to the ground based all-sky imager data, which presents the evolution of the auroral event as the payloads traversed through magnetically similar regions. Current measurements derived from the magnetometers on the high altitude payload observed upward and downward field-aligned currents. The effect of collisions with the neutral atmosphere is investigated to determine it is a significant mechanism to explain discrepancies in the low energy electron flux. The high altitude payload also observed time-dispersed arrivals in the electron flux and perturbations in the electric and magnetic field components, which are indicative of Alfven waves.

  15. Current Closure in the Auroral Ionosphere: Results from the Auroral Current and Electrodynamics Structure Rocket Mission

    NASA Technical Reports Server (NTRS)

    Kaeppler, S. R.; Kletzing, C. A.; Bounds, S. R.; Gjerloev, J. W.; Anderson, B. J.; Korth, H.; LaBelle, J. W.; Dombrowski, M. P.; Lessard, M.; Pfaff, R. F.; Rowland D. E.; Jones, S.; Heinselman, C. J.

    2012-01-01

    The Auroral Current and Electrodynamics Structure (ACES) mission consisted of two sounding rockets launched nearly simultaneously from Poker Flat Research Range, AK on January 29, 2009 into a dynamic multiple-arc aurora. The ACES rocket mission was designed to observe electrodynamic and plasma parameters above and within the current closure region of the auroral ionosphere. Two well instrumented payloads were flown along very similar magnetic field footprints, at different altitudes, with small temporal separation between both payloads. The higher altitude payload (apogee 360 km), obtained in-situ measurements of electrodynamic and plasma parameters above the current closure region to determine the input signature. The low altitude payload (apogee 130 km), made similar observations within the current closure region. Results are presented comparing observations of the electric fields, magnetic components, and the differential electron energy flux at magnetic footpoints common to both payloads. In situ data is compared to the ground based all-sky imager data, which presents the evolution of the auroral event as the payloads traversed through magnetically similar regions. Current measurements derived from the magnetometers on the high altitude payload observed upward and downward field-aligned currents. The effect of collisions with the neutral atmosphere is investigated to determine if it is a significant mechanism to explain discrepancies in the low energy electron flux. The high altitude payload also observed time-dispersed arrivals in the electron flux and perturbations in the electric and magnetic field components, which are indicative of Alfven waves.

  16. Influence of interplanetary magnetic field and solar wind on auroral brightness in different regions

    NASA Astrophysics Data System (ADS)

    Yang, Y. F.; Lu, J. Y.; Wang, J.-S.; Peng, Z.; Zhou, L.

    2013-01-01

    Abstract<p label="1">By integrating and averaging the <span class="hlt">auroral</span> brightness from Polar Ultraviolet Imager <span class="hlt">auroral</span> images, which have the whole <span class="hlt">auroral</span> ovals, and combining the observation data of interplanetary magnetic field (IMF) and solar wind from NASA Operating Missions as a Node on the Internet (OMNI), we investigate the influence of IMF and solar wind on <span class="hlt">auroral</span> <span class="hlt">activities</span>, and analyze the separate roles of the solar wind dynamic pressure, density, and velocity on aurora, respectively. We statistically analyze the relations between the interplanetary conditions and the <span class="hlt">auroral</span> brightness in dawnside, dayside, duskside, and nightside. It is found that the three components of the IMF have different effects on the <span class="hlt">auroral</span> brightness in the different regions. Different from the nightside <span class="hlt">auroral</span> brightness, the dawnside, dayside, and duskside <span class="hlt">auroral</span> brightness are affected by the IMF Bx, and By components more significantly. The IMF Bx and By components have different effects on these three regional <span class="hlt">auroral</span> brightness under the opposite polarities of the IMF Bz. As expected, the nightside aurora is mainly affected by the IMF Bz, and under southward IMF, the larger the |Bz|, the brighter the nightside aurora. The IMF Bx and By components have no visible effects. On the other hand, it is also found that the aurora is not intensified singly with the increase of the solar wind dynamic pressure: when only the dynamic pressure is high, but the solar wind velocity is not very fast, the aurora will not necessarily be intensified significantly. These results can be used to qualitatively predict the <span class="hlt">auroral</span> <span class="hlt">activities</span> in different regions for various interplanetary conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980200997','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980200997"><span id="translatedtitle">Global <span class="hlt">Auroral</span> Imaging for the Dynamics Explorer Mission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Frank, L. A.</p> <p>1998-01-01</p> <p>The two Dynamics Explorer spacecraft, DE-1 and DE-2, were launched on August 3, 1981, into polar coplanar orbits at different altitudes for the purpose of studying interactive processes within the atmosphere-ionosphere-magnetosphere system. The DE-1 spacecraft (high-altitude mission) used an elliptical orbit that was selected to allow: (1) measurements extending from the hot magnetospheric plasma through the plasmasphere to the cool ionosphere; (2) global <span class="hlt">auroral</span> imaging, wave measurements in the heart of the magnetosphere, and crossing of <span class="hlt">auroral</span> field lines at several earth radii; and (3) measurements for significant periods of time along a magnetic field flux tube. The orbit of Dynamics Explorer 1 offered an opportunity to obtain global images of Earth's dayglow and <span class="hlt">auroral</span> luminosities and to acquire consecutive images of the entire <span class="hlt">auroral</span> oval during the growth, onset, expansion, and recovery phases of substorms. The University of Iowa's Spin-scan <span class="hlt">Auroral</span> Imaging (SAI) instrument, was on-board DE-1. SAI was <span class="hlt">activated</span> in orbit and placed in routine operation on September 23, 1981, and has provided outstanding new contributions in the fields of <span class="hlt">auroral</span>, magnetospheric and geocoronal physics, introduced a powerful tool for the study of global atmospheric ozone, and initiated the first search from space for marine bioluminescence on the surface of the global ocean. The SAI instrumentation consists of three imaging photometers, two for visible wavelengths and the third for vacuum-ultraviolet wavelengths equipped with primary catoptric optics with superpolished mirror surfaces. The primary focusing element is an off-axis section of a parabolic mirror that is used to provide an optical path completely free of support structures for the mirrors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790041369&hterms=electromagnetic+earth+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Delectromagnetic%2Bearth%2Bfield','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790041369&hterms=electromagnetic+earth+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Delectromagnetic%2Bearth%2Bfield"><span id="translatedtitle">Electromagnetic plasma wave emissions from the <span class="hlt">auroral</span> field lines</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gurnett, D. A.</p> <p>1978-01-01</p> <p>The most important types of <span class="hlt">auroral</span> radio emissions are reviewed. Particular attention is given to the following four types of electromagnetic emissions: <span class="hlt">auroral</span> hiss, saucers, ELF noise bands, and <span class="hlt">auroral</span> kilometric radiation. It is shown that the <span class="hlt">auroral</span> hiss and <span class="hlt">auroral</span> kilometric radiation are generated along the <span class="hlt">auroral</span> field lines relatively close to the earth, at radial distances in the range of 2.5-5 earth radii, probably in direct association with <span class="hlt">auroral</span>-particle acceleration by parallel electric fields. The <span class="hlt">auroral</span> hiss appears to be generated by amplified Cerenkov radiation. Several mechanisms are proposed for the <span class="hlt">auroral</span> kilometric radiation, usually involving the intermediate generation of electrostatic waves by the precipitating electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990024988','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990024988"><span id="translatedtitle">Localized Ionospheric Particle Acceleration and Wave Acceleration of <span class="hlt">Auroral</span> Ions: Amicist Data Set</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lynch, Kristina A.</p> <p>1999-01-01</p> <p><span class="hlt">Research</span> supported by this grant covered two main topics: <span class="hlt">auroral</span> ion acceleration from ELF-band wave <span class="hlt">activity</span>, and from VLF-spikelet (lower hybrid solitary structure) wave <span class="hlt">activity</span>. Recent <span class="hlt">auroral</span> sounding rocket data illustrate the relative significance of various mechanisms for initiating <span class="hlt">auroral</span> ion outflow. Two nightside mechanisms are shown in detail. The first mechanism is ion acceleration within lower hybrid solitary wave events. The new data from this two payload mission show clearly that: (1) these individual events are spatially localized to scales approximately 100 m wide perpendicular to B, in agreement with previous investigations of these structures, and (2) that the probability of occurrence of the events is greatest at times of maximum VLF wave intensity. The second mechanism is ion acceleration by broadband, low frequency electrostatic waves, observed in a 30 km wide region at the poleward edge of the arc. The ion fluxes from the two mechanisms are compared and it is shown that while lower hybrid solitary structures do indeed accelerate ions in regions of intense VLF waves, the outflow from the electrostatic ion wave acceleration region is dominant for the aurora investigated by this sounding rocket, AMICIST. The fluxes are shown to be consistent with DE-1 and Freja outflow measurements, indicating that the AMICIST observations show the low altitude, microphysical signatures of nightside <span class="hlt">auroral</span> outflow. In this paper, we present a review of sounding rocket observations of the ion acceleration seen nightside <span class="hlt">auroral</span> zone lower hybrid solitary structures. Observations from Topaz3, Amicist, and Phaze2 are presented on various spatial scales, including the two-point measurements of the Amicist mission. From this collection of observations, we will demonstrate the following characteristics of transverse ion acceleration (TAI) in LHSS. The ion acceleration process is narrowly confined to 90 degrees pitch angle, in spatially confined regions of up to a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21512570','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21512570"><span id="translatedtitle">The <span class="hlt">auroral</span> footprint of Enceladus on Saturn.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pryor, Wayne R; Rymer, Abigail M; Mitchell, Donald G; Hill, Thomas W; Young, David T; Saur, Joachim; Jones, Geraint H; Jacobsen, Sven; Cowley, Stan W H; Mauk, Barry H; Coates, Andrew J; Gustin, Jacques; Grodent, Denis; Gérard, Jean-Claude; Lamy, Laurent; Nichols, Jonathan D; Krimigis, Stamatios M; Esposito, Larry W; Dougherty, Michele K; Jouchoux, Alain J; Stewart, A Ian F; McClintock, William E; Holsclaw, Gregory M; Ajello, Joseph M; Colwell, Joshua E; Hendrix, Amanda R; Crary, Frank J; Clarke, John T; Zhou, Xiaoyan</p> <p>2011-04-21</p> <p>Although there are substantial differences between the magnetospheres of Jupiter and Saturn, it has been suggested that cryovolcanic <span class="hlt">activity</span> at Enceladus could lead to electrodynamic coupling between Enceladus and Saturn like that which links Jupiter with Io, Europa and Ganymede. Powerful field-aligned electron beams associated with the Io-Jupiter coupling, for example, create an <span class="hlt">auroral</span> footprint in Jupiter's ionosphere. <span class="hlt">Auroral</span> ultraviolet emission associated with Enceladus-Saturn coupling is anticipated to be just a few tenths of a kilorayleigh (ref. 12), about an order of magnitude dimmer than Io's footprint and below the observable threshold, consistent with its non-detection. Here we report the detection of magnetic-field-aligned ion and electron beams (offset several moon radii downstream from Enceladus) with sufficient power to stimulate detectable aurora, and the subsequent discovery of Enceladus-associated aurora in a few per cent of the scans of the moon's footprint. The footprint varies in emission magnitude more than can plausibly be explained by changes in magnetospheric parameters--and as such is probably indicative of variable plume <span class="hlt">activity</span>. PMID:21512570</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA21B2123M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA21B2123M"><span id="translatedtitle">Statistical study of NEIAL occurence in the PFISR data and correlated <span class="hlt">auroral</span> forms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Michell, R. G.; Samara, M.</p> <p>2012-12-01</p> <p>Naturally Enhanced Ion Acoustic Lines (NEIALs) have been observed wth the Poker Flat Incoherent Scatter Radar (PFISR) ever since it began operating in 2006. The first few years of PFISR operation corresponded to a long, geomagnetically quiet solar minimum. During this time there were only a limited number of NEIALs observed with PFISR with simultaneous <span class="hlt">auroral</span> imaging. The increases in solar <span class="hlt">activity</span> that started occurring in 2011 and 2012 have resulted in significantly more <span class="hlt">active</span> <span class="hlt">auroral</span> structures over the PFISR radar at Poker Flat, AK. The increase in <span class="hlt">auroral</span> <span class="hlt">activity</span> has resulted in a large number of NEIALs observed with PFISR. The MOOSE imagers have been operating continuously since September 2011 and have made many <span class="hlt">auroral</span> observations simultaneous to the PFISR observations of NEIALs. The larger number of NEIAL observations available now, make it possible to distinguish the range of <span class="hlt">auroral</span> features that are associated with different aspects of the NEIAL observations. We aim to statistically catagorize the different types of <span class="hlt">auroral</span> features that occur with NEIALs in the PFISR data, with the goal of gaining insight into the possible generation mechanisms of NEIALs.; PFISR electron density measurements (in 10^11 m^-3) showing strong NEIAL enhancements extending to greater than 700 km altitudes. ; All-sky image from 22 January 2012, showing tall rayed <span class="hlt">auroral</span> structures at a time of strong NEIALs in the PFISR data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Icar..263....2K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Icar..263....2K"><span id="translatedtitle">Saturn kilometric radiation intensities during the Saturn <span class="hlt">auroral</span> campaign of 2013</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kurth, W. S.; Hospodarsky, G. B.; Gurnett, D. A.; Lamy, L.; Dougherty, M. K.; Nichols, J.; Bunce, E. J.; Pryor, W.; Baines, K.; Stallard, T.; Melin, H.; Crary, F. J.</p> <p>2016-01-01</p> <p>The Saturn <span class="hlt">auroral</span> campaign carried out in the spring of 2013 used multiple Earth-based observations, remote-sensing observations from Cassini, and in situ-observations from Cassini to further our understanding of auroras at Saturn. Most of the remote sensing and Earth-based measurements are, by nature, not continuous. And, even the in situ measurements, while continuously obtained, are not always obtained in regions relevant to the study of the aurora. Saturn kilometric radiation, however, is remotely monitored nearly continuously by the Radio and Plasma Wave Science instrument on Cassini. This radio emission, produced by the cyclotron maser instability, is tightly tied to <span class="hlt">auroral</span> processes at Saturn as are <span class="hlt">auroral</span> radio emissions at other planets, most notably Jupiter and Earth. This paper provides the time history of the intensity of the radio emissions through the <span class="hlt">auroral</span> campaign as a means of understanding the temporal relationships between the sometimes widely spaced observations of the <span class="hlt">auroral</span> <span class="hlt">activity</span>. While beaming characteristics of the radio emissions are known to prevent single spacecraft observations of this emission from being a perfect <span class="hlt">auroral</span> <span class="hlt">activity</span> indicator, we demonstrate a good correlation between the radio emission intensity and the level of UV <span class="hlt">auroral</span> <span class="hlt">activity</span>, when both measurements are available.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=15832&keyword=activity+AND+Physics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=66684210&CFTOKEN=10911855','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=15832&keyword=activity+AND+Physics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=66684210&CFTOKEN=10911855"><span id="translatedtitle">PM <span class="hlt">ACTIVITY</span> PATTERN <span class="hlt">RESEARCH</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Human <span class="hlt">activity</span>/uptake rate data are necessary to estimate potential human exposure and intake dose to environmental pollutants and to refine human exposure models. Personal exposure monitoring studies have demonstrated the critical role that <span class="hlt">activities</span> play in explaining and pre...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997AnGeo..15..959S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997AnGeo..15..959S"><span id="translatedtitle">Luminosity variations in several parallel <span class="hlt">auroral</span> arcs before <span class="hlt">auroral</span> breakup</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Safargaleev, V.; Lyatsky, W.; Tagirov, V.</p> <p>1997-08-01</p> <p>Variation of the luminosity in two parallel <span class="hlt">auroral</span> arcs before <span class="hlt">auroral</span> breakup has been studied by using digitised TV-data with high temporal and spatial resolution. The intervals when a new arc appears near already existing one were chosen for analysis. It is shown, for all cases, that the appearance of a new arc is accompanied by fading or disappearance of another arc. We have named these events out-of-phase events, OP. Another type of luminosity variation is characterised by almost simultaneous enhancement of intensity in the both arcs (in-phase event, IP). The characteristic time of IP events is 10-20 s, whereas OP events last about one minute. Sometimes out-of-phase events begin as IP events. The possible mechanisms for OP and IP events are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=MATT&pg=5&id=EJ463304','ERIC'); return false;" href="http://eric.ed.gov/?q=MATT&pg=5&id=EJ463304"><span id="translatedtitle">Ethics in Physical <span class="hlt">Activity</span> <span class="hlt">Research</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kroll, Walter; And Others</p> <p>1993-01-01</p> <p>Four conference papers on ethics in physical <span class="hlt">activity</span> <span class="hlt">research</span> are presented: (1) "Ethical Issues in Human <span class="hlt">Research</span>" (W. Kroll); (2) "Ethical Issues in Animal <span class="hlt">Research</span>" (K. Matt); (3) "Oh What a Tangled Web We Have" (M. Safrit); and (4) "Ethical Issues in Conducting and Reporting <span class="hlt">Research</span>: A Reaction to Kroll, Matt, and Safrit" (H. Zelaznik). (SM)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007APS..DPPVI2004R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007APS..DPPVI2004R"><span id="translatedtitle">Laboratory study of <span class="hlt">auroral</span> cyclotron emission processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ronald, Kevin</p> <p>2007-11-01</p> <p>Electrons encounter an increasing magnetic field and increase in pitch angle as they descend towards the <span class="hlt">auroral</span> ionosphere, according to the conservation of the magnetic moment. This process results in a horseshoe shaped distribution function in electron velocity space which has been observed by satellites [1]. <span class="hlt">Research</span> has shown this distribution to be unstable to a cyclotron maser instability [2] and the emitted <span class="hlt">Auroral</span> Kilometric Radiation is observed to be polarised in the extraordinary mode. Experimental results are presented based on an electron beam of energy 75keV having a cyclotron frequency of 4.45GHz, compressed using magnet coils to mimic the naturally occurring phenomenon. The emitted radiation spectrum was observed to be close to the cyclotron frequency. Electron transport measurements confirmed that the horseshoe distribution function was obtained. Measurements of the antenna pattern radiated from the output window demonstrated the radiation to be polarised and propagating perpendicular to the static magnetic field. The radiation generation efficiency was estimated to be 2% in close agreement to the numerical predictions of the 2D PiC code KARAT. The efficiency was also comparable with estimates of the astrophysical phenomenon. [1] R. J. Strangeway et al, Geophys. Rev. Lett., 25, 1998, pp. 2065-2068 [2] I Vorgul et al, Physics of Plasmas, 12, 2005, pp. 1-8</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750010749','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750010749"><span id="translatedtitle">Magnetospheric and <span class="hlt">auroral</span> plasmas: A short survey of progress, 1971 - 1975</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Frank, L. A.</p> <p>1975-01-01</p> <p>Milestones in <span class="hlt">researches</span> of <span class="hlt">auroral</span> and magnetospheric plasmas for the past quadrennium 1971 - 1975 are reviewed. Findings, including those of the polar cusp, the polar wind, the explosive disruptions of the magnetotail, the interactions of hot plasmas with the plasmapause, the <span class="hlt">auroral</span> field-aligned currents, and the striking 'inverted-V' electron precipitation events, are reported. Solutions to major questions concerning the origins and acceleration of these plasmas are discussed. A comprehensive bibliography of current <span class="hlt">research</span> is included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMSM23A0467Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMSM23A0467Y"><span id="translatedtitle">Further Studies of Flickering <span class="hlt">Auroral</span> Roar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ye, S.; Labelle, J.; Weatherwax, A.</p> <p>2004-12-01</p> <p>In December 2002, a Versatile Electromagnetic Wave Receiver (VIEW) was deployed at South Pole station. This system records HF waveforms continuously for up to 6 hours/day. Summary files are examined weekly by Dartmouth personnel, and interesting time intervals are saved to CD-rom. This interactive experimental method provides extremely high time- and frequency-resolution measurements of <span class="hlt">auroral</span> radio emissions, while discarding data from times when no events occur. The motivation was to measure three types of <span class="hlt">auroral</span> radio emissions: <span class="hlt">Auroral</span> Roar, a relatively narrowband (δf/f <0.1) emission near 2 and 3 times the F region ionospheric electron cyclotron frequency (fce); <span class="hlt">Auroral</span> Hiss, a whistler mode wave emission with frequencies lower than 1MHz. ; and <span class="hlt">Auroral</span> medium frequency (MF) burst, broadband impulsive radio emissions observed at ground level during the breakup phase of <span class="hlt">auroral</span> substorms. In the year of 2003, we recorded about 80 minutes of <span class="hlt">auroral</span> roar emission, consisting of 40 different events, at South Pole station. Hughes and LaBelle [2001] observed the first flickering <span class="hlt">auroral</span> roar, with a ~10 Hz pulsation in emission strength, in Greenland. They proposed that these pulsations are related to the electron flux modulations similar to those which cause flickering aurora. By examining all 80 minutes (40 events) of <span class="hlt">auroral</span> roar captured in 2003, we found more than 10 cases of flickering <span class="hlt">auroral</span> roar from 10 different days. However, most instances were brief, sometimes only a few seconds. The total time of flickering <span class="hlt">auroral</span> roar was a few minutes (a few percent of the total time of occurrence of <span class="hlt">auroral</span> roar emissions). We also observed the first ever example of higher frequency flickering <span class="hlt">auroral</span> roar, with a modulation frequency around 100 Hz. We investigate these events by taking time series of the strength of the <span class="hlt">auroral</span> roar emissions, taking Fourier transforms to determine the frequencies of the flickering. In this poster, we show statistics of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910017323','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910017323"><span id="translatedtitle">Theoretical and experimental studies relevant to interpretation of <span class="hlt">auroral</span> emissions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Keffer, Charles E.</p> <p>1991-01-01</p> <p>The accomplishments achieved over the past year are detailed with emphasis on the interpretation or <span class="hlt">auroral</span> emissions and studies of potential spacecraft-induced contamination effects. Accordingly, the <span class="hlt">research</span> was divided into two tasks. The first task is designed to add to the understanding of space vehicle induced external contamination. An experimental facility for simulation of the external environment for a spacecraft in low earth orbit was developed. The facility was used to make laboratory measurements of important phenomena required for improving the understanding of the space vehicle induced external environment and its effect on measurement of <span class="hlt">auroral</span> emissions from space-based platforms. A workshop was sponsored to provide a forum for presentation of the latest <span class="hlt">research</span> by nationally recognized experts on space vehicle contamination and to discuss the impact of this <span class="hlt">research</span> on future missions involving space-based platforms. The second task is to add an ab initio <span class="hlt">auroral</span> calculation to the extant ionospheric/thermospheric global modeling capabilities. Once the addition of the code was complete, the combined model was to be used to compare the relative intensities and behavior of various emission sources (dayglow, aurora, etc.). Such studies are essential to an understanding of the types of vacuum ultraviolet (VUV) <span class="hlt">auroral</span> images which are expected to be available within two years with the successful deployment of the Ultraviolet Imager (UVI) on the ISTP POLAR spacecraft. In anticipation of this, the second task includes support for meetings of the science working group for the UVI to discuss operational and data analysis needs. Taken together, the proposed tasks outline a course of study designed to make significant contributions to the field of space-based <span class="hlt">auroral</span> imaging.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/7871430','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/7871430"><span id="translatedtitle"><span class="hlt">Auroral</span> signature of comet Shoemaker-Levy 9 in the jovian magnetosphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Prangé, R; Engle, I M; Clarke, J T; Dunlop, M; Ballester, G E; Ip, W H; Maurice, S; Trauger, J</p> <p>1995-03-01</p> <p>The electrodynamic interaction of the dust and gas comae of comet Shoemaker-Levy 9 with the jovian magnetosphere was unique and different from the atmospheric effects. Early theoretical predictions of <span class="hlt">auroral</span>-type processes on the comet magnetic field line and advanced modeling of the time-varying morphology of these lines allowed dedicated observations with the Hubble Space Telescope Wide Field Planetary Camera 2 and resulted in the detection of a bright <span class="hlt">auroral</span> spot. In that respect, this observation of the surface signature of an externally triggered <span class="hlt">auroral</span> process can be considered as a "magnetospheric <span class="hlt">active</span> experiment" on Jupiter. PMID:7871430</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFMED22C..06S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFMED22C..06S&link_type=ABSTRACT"><span id="translatedtitle">Interactive <span class="hlt">Auroral</span> Science for Hearing-Impaired Students</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Samara, M.; Michell, R. G.; Jahn, J.; Pfeifer, M.; Ibarra, S.; Hampton, D. L.; Powell, D.</p> <p>2012-12-01</p> <p>Under a NASA E/PO grant, we have partnered with San Antonio's Sunshine Cottage School for Deaf Children to develop a science class experience where students directly interact with scientists and participate in a <span class="hlt">research</span>-grade space science measurement campaign. The unique aspect of partnering with Sunshine Cottage lies in Sunshine's approach of auditory-verbal communication. Aided by technology (hearing aids, cochlear implants), a diverse student body with students of all levels of hearing loss (moderate through profound) is taught in an entirely auditory-verbal environment at Sunshine Cottage. Bringing these students into early contact with <span class="hlt">research</span> work can lay the foundation for future careers in the STEM field that normally they might not consider as indicated by the first year of this collaboration where the student response was distinctly positive. Here we report on the first year of those <span class="hlt">activities</span>, as they related to a ground based imaging approach to exploring the northern lights and from the point of view of the scientists that participated. The major components of that <span class="hlt">activity</span> included a site visit to SwRI by the students and their teachers, a semester long lab at school utilizing current <span class="hlt">research</span> tools and a real-time campaign night. The students used a number of diagnostics to first predict and then verify <span class="hlt">auroral</span> <span class="hlt">activity</span>. One of the tools used was the MOOSE observatory which is a community resource state of the art observatory comprised of 5 EMCCD imagers in Alaska, established through an NSF MRI grant. We will discuss the approach and lessons learned during the first year of the project and the directions that we will likely take in the second year. Lessons learned from teaching these students space science related topic can be flowed right back into mainstream classroom settings. One other significant and unexpected aspect of this first year was that we were able to connect two groups of students through skype (in the 4th to 5th grades) that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AdSpR..55.1349S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AdSpR..55.1349S"><span id="translatedtitle"><span class="hlt">Auroral</span> electrojets during severely disturbed geomagnetic condition on 24 August 2005</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Anand K.; Sinha, A. K.; Saini, S.; Rawat, Rahul</p> <p>2015-03-01</p> <p>Very intense and highly dynamic eastward and westward currents flowing in the <span class="hlt">auroral</span> ionosphere are traditionally monitored by the <span class="hlt">auroral</span> electrojet indices - AUand AL , respectively. In this study we show that on occasions of intense magnetic <span class="hlt">activity</span>, entire <span class="hlt">auroral</span> oval could be dominated by the westward flowing currents, which lead to depression not only in AL index but also in supposedly positive AU index. During negative AU intervals, there could be up to ∼ 20 % underestimation of the total maximum intensity of the <span class="hlt">auroral</span> electrojet represented by AEindex (defined as AU - AL). A detailed investigation of a well-studied extremely intense event of 24 August 2005 has been carried out. Global prevalence of the westward <span class="hlt">auroral</span> electrojet was clearly observed at the <span class="hlt">auroral</span> latitudes during the unusually intense substorm (AL ∼ - 4000 nT) on the day. Moreover, along the noon meridian westward electrojet appeared in the <span class="hlt">auroral</span> region whereas eastward electrojet shifted towards lower latitudes. This paper emphasizes that intense substorms are represented better by AL index than AE index.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992bc...rept.....C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992bc...rept.....C"><span id="translatedtitle">The earth's radiation belts, <span class="hlt">auroral</span> zones, and polar caps: Particle models, event studies, and effects on materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carovillano, R. L.</p> <p>1992-04-01</p> <p>Some <span class="hlt">research</span> <span class="hlt">activities</span> are as follows. (1) An empirical DMSP data base of the most poleward ion precipitation boundary: The data base was analyzed statistically and analytically. At each MLT there is great variance, and the ion boundary correlates best with AE. The average boundary is a circle offset from the geomagnetic pole that expands with geomagnetic <span class="hlt">activity</span>. (2) An analytical model of convection and currents in the height-integrated ionosphere coupled to field aligned currents: Results include the effect of <span class="hlt">auroral</span> conductivity; the deterministic coupling between Region 1 and Region 2 currents; the generation of <span class="hlt">auroral</span> electrojet currents; the electrical shielding of low latitudes; two cell and multiple cell convection patterns; and conductivity gradient effects. (3) Energy dispersion discovered at the ion polar cap boundary: Interpretations have the ions originating in the plasma sheet boundary layer. (4) Various tasks and services with Air Force data bases: Tasks included particle event studies, the <span class="hlt">auroral</span> boundary index, the polar rain index, and several CRRES projects including the static radiation belt model. Services included algorithm development, provision for data storage, access, and documentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFMED41A3425S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFMED41A3425S&link_type=ABSTRACT"><span id="translatedtitle">Study of Motion of the <span class="hlt">Auroral</span> Oval During September 30 - October 4, 2012 Geomagnetic Storm. A Project of National Secondary School Competition in Scientific <span class="hlt">Research</span> on Antarctica "Feria Antarctica Escolar 2014", organized by Chilean Antarctic Institute (INACH).</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stepanova, M. V.; Cabezas-Escares, J. F.; Letelier-Ulloa, T. C.; Ortega-Letelier, P.</p> <p>2014-12-01</p> <p>Changes in the position of the <span class="hlt">auroral</span> oval during the development of the September 30 - October 4, 2012 geomagnetic storm in both Northern and Southern Hemispheres were studied using the data of the Dynamics Explorer Satellite Mission (DMSP). In particular, the location of b1e, b1i, b2e, and b2i boundaries defined by Newell at al. [1996], was obtained from the electron and ion precipitating fluxes, measured by the SSJ/4 particle detectors onboard the F16, F17, and F18 satellites.According to Newell at al. [1996], these boundaries represent the zero-energy convection boundary (b1e,b1i), and the precipitating energy flux maximum (b2e,b2i). It was found that during the main phase of the strom, on average, all boundaries move towards the equator, and return to its previous location during recovery phase. Deviations from the common trend could be related to the changes in the solar wind conditions. This study was done by the Secondary school students Javiera Cabezas-Escares and Tamara Letelier Ulloa from Lyceum N°1 Javiera Carrera in frame of the National Secondary School Competition in the Scientific <span class="hlt">Research</span> on Antarctica "Feria Antarctica Escolar" organized by Chilean Antarctic Institute. It was supervised by their Physics teacher Pablo Ortega Letelier and by Marina Stepanova, <span class="hlt">researcher</span> from Universidad de Santiago de Chile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007DPS....39.0408S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007DPS....39.0408S"><span id="translatedtitle">Magnetic Reconnection Indicated in Jupiter's H3+ <span class="hlt">Auroral</span> Flux Variations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Satoh, Takehiko; Connerney, J. E.; Morioka, A.; Tokumaru, M.; Hayashi, K.</p> <p>2007-10-01</p> <p>Due to its complexity, the production mechanism of Jupiter's powerful aurora is to date not very well understood. Possible correlation with the solar wind has been one of such unsolved problems (Prange et al. 1993; Baron et al., 1996; Gurnet et al., 2002). We analyzed several sets of ground-based infrared data of Jupiter's H3+ aurora, acquired at NASA/IRTF atop Mauna Kea, Hawaii during 1998-2000 seasons. Night-to-night variations of total <span class="hlt">auroral</span> flux are measured in images and are compared with the solar wind parameters at Jupiter's orbit. The solar wind parameters used in this study have been numerically inferred using a MHD tomography based on the interplanetary scintillation (IPS) observations (Hayashi et al., 2003).This method reconstructs the global structure of corotating solar wind assuming that such structure exists steadily during one Carrington rotation. Because of this assumption, transient changes of the solar wind can not be reproduced. As Jupiter's H3+ aurora is believed to reflect "time-averaged" magnetospheric <span class="hlt">activities</span>, the solar wind parameters with 1-day time resolution is still a useful index. We evaluated the solar-wind dynamic pressure P and the reconnection voltage φ (Nichols et al., 2006) for the period of <span class="hlt">auroral</span> observations. These two quantities are then converted to possible changes of magnetic flux density in Jupiter's magnetosphere. Neither of these two can explain the <span class="hlt">auroral</span> flux vatiations solely. However, it is found that combining these two quantities (with slight adjustments) could better explain the increases/decreases of <span class="hlt">auroral</span> flux. Amplitudes of the <span class="hlt">auroral</span> flux variations, as well as uncertainties due to "extrapolation" of solar wind parameters to Jupiter's orbit will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM13F4235W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM13F4235W"><span id="translatedtitle">Automatic Georeferencing of Astronaut <span class="hlt">Auroral</span> Photography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walsh, A. P.; Riechert, M.; Taylor, M. G.</p> <p>2014-12-01</p> <p>Astronauts on board the International Space Station have taken thousands of high quality photographs of the aurorae borealis and australis with a high temporal and spatial resolution. A barrier to these photographs being used in <span class="hlt">research</span> is that the cameras do not have a fixed orientation and the images therefore do not have any pointing information associated with them. Using astrometry.net and other open source libraries we have developed a software toolkit to automatically reconstruct the pointing of the images from the visible starfield and hence project the <span class="hlt">auroral</span> images in geographic and geomagnetic coordinates. Here we explain the technique and the resulting data products, which will soon be publically available through the project website.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6444180','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6444180"><span id="translatedtitle">Electron precipitation in the midday <span class="hlt">auroral</span> oval</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Meng, C.</p> <p>1981-04-01</p> <p>Simultaneous observations of <span class="hlt">auroral</span> displays and electron precipitations by the DMSP 33 satellite provide an excellent and unique opportunity to study precipitation characteristics of the midday <span class="hlt">auroral</span> oval. Attention is given to two topics: (1) the nature of the 'gap' of the midday discrete auroras which is a permanent feature of the dayside <span class="hlt">auroral</span> oval observed by both Isis 2 and DMSP satellites and (2) the relationship of this gap with the polar cusp region. Based on 2-month (June, July 1975) observations of the midday auroras over the southern hemisphere, it is found that inside the 'gap' of the discrete auroras along the dayside <span class="hlt">auroral</span> oval, soft electron precipitations with a magnetosheathlike spectrum were invariably detected. The spatial extent of this region was about few degrees in latitude and about 2--3 hours in local time near 1130 magnetic local time meridian. No significant electron precipitation was detected poleward of the instantaneous midday <span class="hlt">auroral</span> oval. Typical plasma sheet and discrete <span class="hlt">auroral</span> types of electron precipitations were detected in the other parts of the midday <span class="hlt">auroral</span> oval. Therefore it is proposed that the ionospheric projection of the polar cusp is a small region of the instantaneous dayside <span class="hlt">auroral</span> oval near the noon meridian, coinciding with the 'gap' of the midday discrete auroras.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=tunnel+AND+wind&pg=3&id=ED337684','ERIC'); return false;" href="http://eric.ed.gov/?q=tunnel+AND+wind&pg=3&id=ED337684"><span id="translatedtitle"><span class="hlt">Research</span> and Development. Laboratory <span class="hlt">Activities</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gallaway, Ann, Ed.</p> <p></p> <p><span class="hlt">Research</span> and Development is a laboratory-oriented course that includes the appropriate common essential elements for industrial technology education plus concepts and skills related to <span class="hlt">research</span> and development. This guide provides teachers of the course with learning <span class="hlt">activities</span> for secondary students. Introductory materials include an…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5439986','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5439986"><span id="translatedtitle">The <span class="hlt">auroral</span> radiating plasma cavities</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hilgers, A. )</p> <p>1992-02-07</p> <p>The electron density profile of the nightside high latitude region has been determined from a geocentric distance 1.5 R{sub E} to 3 R{sub E} by the use of the Viking Langmuir probe. Inside this region, density depletions are observed. Most of them coincide with acceleration structure crossings. Generation of <span class="hlt">Auroral</span> Kilometric Radiation (AKR) is observed in the strongest depletions between 1.5 and 2.5 R{sub E}. A threshold on the ratio plasma to electron gyrofrequency for AKR generation to occur is estimated at 0.14. This is in good agreement with the cyclotron maser instability theory for AKR generation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030061175&hterms=simultaneous&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsimultaneous','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030061175&hterms=simultaneous&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsimultaneous"><span id="translatedtitle">Preliminary Results from Recent Simultaneous Chandra/HST Observations of Jupiter <span class="hlt">Auroral</span> Zones</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Elsner, R.; Gladstone, R.; Waite, H.; Majeed, T.; Ford, P.; Grodent, D.; Bwardwaj, A.; Howell, R.; Cravens, T.; MacDowell, R.</p> <p>2003-01-01</p> <p>Jupiter was observed by the Chandra X-ray Observatory in late February, 2003, for 144 ks, using both the ACIS-S and HRC-I imaging x-ray cameras. Five orbits of HST STIS observations of the planet's northern <span class="hlt">auroral</span> zone were obtained during the ACIS-S observations. These data are providing a wealth of information about Jupiter's <span class="hlt">auroral</span> <span class="hlt">activity</span>, including the first x-ray spectra from the x-ray hot spots inside the <span class="hlt">auroral</span> ovals. We will also discuss the approximately 45 minute quasi-periodicity in the <span class="hlt">auroral</span> x-ray emission - which correlates well with simultaneous observations of radio bursts by the Ulysses spacecraft - and a possible phase relation between the emission from the northern and southern x-ray aurora.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990100917&hterms=night+glow&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dnight%2Bglow','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990100917&hterms=night+glow&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dnight%2Bglow"><span id="translatedtitle">Evidence for Directly Driven <span class="hlt">Auroral</span> Signatures Resulting from Interplanetary Pressure Pulses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spann, J. F., Jr.; Brittnacher, M. J.; Parks, G. K.; Germany, G. A.</p> <p>1999-01-01</p> <p>It has been observed that the <span class="hlt">auroral</span> signature of the arrival of an interplanetary pressure pulse at the bow shock causes an initial brightening near noon. Consequently, the bright region propagates to the night side via the dawn and dusk flanks. The delay time for subsequent <span class="hlt">auroral</span> breakup is observed to vary significantly from seconds to hours. We have examined the 1998 and early 1999 interplanetary pressure pulse events recorded by WIND and ACE (over 35 in all) and correlated these with the Polar UVI data for the events that are imaged. Evidence for directly driven <span class="hlt">auroral</span> <span class="hlt">activity</span> resulting from an interplanetary pressure pulse will be discussed as well as the variation of the delay time for <span class="hlt">auroral</span> breakup.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=professionalism+AND+human+AND+resource&pg=2&id=EJ437574','ERIC'); return false;" href="http://eric.ed.gov/?q=professionalism+AND+human+AND+resource&pg=2&id=EJ437574"><span id="translatedtitle">Recent <span class="hlt">Research</span> <span class="hlt">Activity</span> at OECD.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Economics of Education Review, 1991</p> <p>1991-01-01</p> <p>Summarizes <span class="hlt">research</span> topics and <span class="hlt">activities</span> at upcoming and past conferences involving the Organisation for Economic Cooperation and Development. Human resources <span class="hlt">activity</span> is stressing partnerships and the adult learner. New policies and direction in teacher education are focusing on the new professionalism and training innovations. Imbalances in the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790064332&hterms=auroral+region+electric+potential+structure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dauroral%2Bregion%2Belectric%2Bpotential%2Bstructure','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790064332&hterms=auroral+region+electric+potential+structure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dauroral%2Bregion%2Belectric%2Bpotential%2Bstructure"><span id="translatedtitle">Simulation of <span class="hlt">auroral</span> double layers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hubbard, R. F.; Joyce, G.</p> <p>1979-01-01</p> <p>Some basic properties of plasma double layers are deduced from a particle-in-cell computer simulation and related to parallel electric-field structures above the <span class="hlt">auroral</span> regions. The simulation results on the processes leading to double-layer formation are examined, particularly in relation to the transient stage and double-layer structure and stability. It is concluded that: (1) a large potential difference applied to a finite-length plasma will be concentrated in a shocklike localized region instead of occurring over the entire length of the system; (2) the initial stage in double-layer formation is dominated by a large-potential pulse propagating in the direction of the induced electrostatic drift; (3) the entire potential is dropped over a specific scale length once the double layer has formed; and (4) this scale length is expected to be of the order of 1 km for a double layer above a discrete <span class="hlt">auroral</span> arc with a potential of 10 kV and the electric-field vector parallel to the magnetic-field vector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920068571&hterms=polar+bears&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpolar%2Bbears','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920068571&hterms=polar+bears&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpolar%2Bbears"><span id="translatedtitle">Determining the source region of <span class="hlt">auroral</span> emissions in the prenoon oval using coordinated Polar BEAR UV-imaging and DMSP particle measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Newell, Patrick T.; Meng, CHING-I.; Huffman, Robert E.</p> <p>1992-01-01</p> <p>The Polar Beacon Experiment and <span class="hlt">Auroral</span> <span class="hlt">Research</span> (Polar BEAR) satellite included the capability for imaging the dayside <span class="hlt">auroral</span> oval in full sunlight at several wavelengths. Particle observations from the DMSP F7 satellite during dayside <span class="hlt">auroral</span> oval crossings are compared with approximately simultaneous Polar BEAR 1356-A images to determine the magnetospheric source region of the dayside <span class="hlt">auroral</span> oval. The source region is determined from the DMSP particle data, according to recent work concerning the classification and identification of precipitation source regions. The close DMSP/Polar BEAR coincidences all occur when the former satellite is located between 0945 and 1000 MLT. Instances of <span class="hlt">auroral</span> arcs mapping to each of several different regions, including the boundary plasma sheet, the low-latitude boundary layer, and the plasma mantle were found. It was determined that about half the time the most prominent <span class="hlt">auroral</span> arcs are located at the interfaces between distinct plasma regions, at least at the local time studied here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19770044475&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnike','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19770044475&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnike"><span id="translatedtitle">Rocket measurements of electrons in a system of multiple <span class="hlt">auroral</span> arcs</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Boyd, J. S.; Davis, T. N.</p> <p>1977-01-01</p> <p>A Nike-Tomahawk rocket was launched into a system of <span class="hlt">auroral</span> arcs northward of Poker Flat <span class="hlt">Research</span> Range, Fairbanks, Alaska. The pitch-angle distribution of electrons was measured at 2.5, 5, and 10 keV and also at 10 keV on a separating forward section of the payload. The <span class="hlt">auroral</span> <span class="hlt">activity</span> appeared to be the extension of substorm <span class="hlt">activity</span> centered to the east. The rocket crossed a westward-propagating fold in the brightest band. The electron spectrum was relatively hard through most of the flight, showing a peak in the range from 2.5 to 10 keV in the weaker aurora and below 5 keV in the brightest arc. The detailed structure of the pitch-angle distribution suggested that, at times, a very selective process was accelerating some electrons in the magnetic field direction, so that a narrow field-aligned component appeared superimposed on a more isotropic distribution. It is concluded that this process could not be a near-ionosphere field-aligned potential drop, although the more isotropic component may have been produced by a parallel electric field extending several thousand kilometers along the field line above the ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992STIN...9330025.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992STIN...9330025."><span id="translatedtitle"><span class="hlt">Activities</span> report of PTT <span class="hlt">Research</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p></p> <p></p> <p>In the field of postal infrastructure <span class="hlt">research</span>, <span class="hlt">activities</span> were performed on postcode readers, radiolabels, and techniques of operations <span class="hlt">research</span> and artificial intelligence. In the field of telecommunication, transportation, and information, <span class="hlt">research</span> was made on multipurpose coding schemes, speech recognition, hypertext, a multimedia information server, security of electronic data interchange, document retrieval, improvement of the quality of user interfaces, domotics living support (techniques), and standardization of telecommunication prototcols. In the field of telecommunication infrastructure and provisions <span class="hlt">research</span>, <span class="hlt">activities</span> were performed on universal personal telecommunications, advanced broadband network technologies, coherent techniques, measurement of audio quality, near field facilities, local beam communication, local area networks, network security, coupling of broadband and narrowband integrated services digital networks, digital mapping, and standardization of protocols.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSA13B1888S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSA13B1888S"><span id="translatedtitle">Event Study of the Peak <span class="hlt">Auroral</span> Emission Altitude from All-sky Images</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sangalli, L.; Gustavsson, B.; Partamies, N. J.; Kauristie, K.</p> <p>2011-12-01</p> <p>The MIRACLE network monitors <span class="hlt">auroral</span> <span class="hlt">activity</span> in the Fennoscandian sector of Europe. Network stations cover the range of 55° to 57° magnetic latitude North and span two hours in magnetic local time. Some of the MIRACLE network stations include digital all-sky cameras (ASC). Some of the ASCs currently in use are: systems with an image intensifier in front of a CCD (iCCD), systems with electron multiplying CCD (emCCD). Both iCCD and emCCD cameras in the MIRACLE network operate at three different wavelengths: 427.8 nm, 557.7 nm and 630.0 nm. Each wavelength is selected using narrow band filters on a filter wheel placed in front of the CCD. Our goal is to evaluate the peak <span class="hlt">auroral</span> emission altitude using ASC images at different stations pairs for a set of <span class="hlt">auroral</span> event in order to evaluate the altitude of peak <span class="hlt">auroral</span> emissions for different <span class="hlt">auroral</span> structures. We adapted the AIDA software package developed by Björn Gustavsson in Kiruna for ASC images. Position calibrated images at two (or more) ASC stations are for optical triangulation of a set of <span class="hlt">auroral</span> structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19750050946&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnike','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19750050946&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnike"><span id="translatedtitle">Electron currents associated with an <span class="hlt">auroral</span> band</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spiger, R. J.; Anderson, H. R.</p> <p>1975-01-01</p> <p>Measurements of electron pitch angle distributions and energy spectra over a broad <span class="hlt">auroral</span> band were used to calculate net electric current carried by <span class="hlt">auroral</span> electrons in the vicinity of the band. The particle energy spectrometers were carried by a Nike-Tomahawk rocket launched from Poker Flat, Alaska, at 0722 UT on February 25, 1972. Data are presented which indicate the existence of upward field-aligned currents of electrons in the energy range 0.5-20 keV. The spatial relationship of these currents to visual structure of the <span class="hlt">auroral</span> arc and the characteristics of the electrons carrying the currents are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5245868','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5245868"><span id="translatedtitle">Weak <span class="hlt">auroral</span> emissions and particle precipitations in the dusk <span class="hlt">auroral</span> oval</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ono, T.; Hirasawa, T. ); Ching-I. Meng )</p> <p>1989-09-01</p> <p>Faint <span class="hlt">auroral</span> displays in the low-latitude region of the duskside <span class="hlt">auroral</span> oval were examined by using 5577 A, 6300 A, and 4861 A <span class="hlt">auroral</span> images from three monochromatic all-sky television cameras at Syowa Station, Antarctica, and simultaneous precipitating <span class="hlt">auroral</span> particle data obtained by the U.S. Air Force/Defense Meteorological Satellite Program (USAF/DMSP) F6 satellite. In the low-latitude region of the duskside <span class="hlt">auroral</span> oval, we found three types of <span class="hlt">auroral</span> displays with weak optical intensity: (1) proton auroras, (2) pulsating auroras, and (3) faint discrete <span class="hlt">auroral</span> arcs distinct only in the 6300 A emission. In usual cases, the energy input into this region is mostly carried y proton precipitations to produce proton auroras mainly at wavelengths of 4861 A and 5577 A. Pulsating features are sometimes observed in the diffuse <span class="hlt">auroral</span> region in the dusk sector. Comparing <span class="hlt">auroral</span> images with the nearly simultaneous data of precipitating <span class="hlt">auroral</span> particles, we confirmed that the pulsating auroras are associated with the intensification of precipitating electron flux from the central plasma sheet. Furthermore, electrons are the main contributors to the energy input into the duskside <span class="hlt">auroral</span> oval in this case. We also found that discrete auroras sometimes appeared in the 6300 A images, but not in images at other wavelengths. They appear in the equatorial part of the dusk <span class="hlt">auroral</span> oval. These 6300 A discrete auroras correspond to weak precipitation spikes of low-energy electrons simultaneously measured by DMSP satellites. The flux and average energy of these electron spikes are about 10{sup 8}/(cm{sup 2} sr s) and 100 eV, respectively. They are intense enough to excite 6300 A emissions but not 5577 A emissions, as detected from the ground observations. {copyright} American Geophysical Union 1989</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFMSM11C..03P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFMSM11C..03P"><span id="translatedtitle">The Mysteries of <span class="hlt">Auroral</span> X-rays: Then and Now</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parks, G. K.</p> <p>2001-12-01</p> <p>This talk will review the history of <span class="hlt">auroral</span> X-ray observations and their contributions to magnetospheric physics. X-rays were first discovered in the magnetic storm of July 1, 1957 over Minneapolis by John Winckler's <span class="hlt">research</span> group. A cosmic ray particle experiment aloft a balloon detected an anomalous increase in counting rate that was later deduced to be atmospheric bremsstrahlung X-rays from precipitated energetic electrons. X-ray experiments subsequently carried out from the <span class="hlt">auroral</span> zone yielded the important information that precipitated electrons are highly structured in space and time. Periodic 5-30s pulsations dominate the early morning sector, while =1s microbursts in the dawn to noon sector. Satellite observations have now obtained global features about the energetic electron precipitation. Most of the <span class="hlt">auroral</span> X-rays have energies =20-100 keV but recent data indicate that electron precipitation frequently involves intense bursts of X-rays with MeV energies. John Winckler led the way on an exciting path that extends into the future, as <span class="hlt">researchers</span> will continue to delve into the mystery of source mechanisms of pulsations, microbursts and the MeV X-rays.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002JGRA..107.1381S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002JGRA..107.1381S"><span id="translatedtitle"><span class="hlt">Auroral</span> kilometric radiation source characteristics using ray tracing techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schreiber, R.; Santolik, O.; Parrot, M.; Lefeuvre, F.; Hanasz, J.; Brittnacher, M.; Parks, G.</p> <p>2002-11-01</p> <p>3-D ray tracing to the presumed <span class="hlt">auroral</span> kilometric radiation (AKR) source region has been performed using the input data from wave distribution function (WDF) based on the AKR waveforms recorded on board the Interball 2 satellite by the French wave experiment MEMO. Both the direction of the WDF maximum and the WDF form and angular size have been taken into account. Two instances of AKR emissions were observed on 28 January 1997 at 2037 and 2107 UT. Rays traced in R-X mode out of the s/c point toward two different <span class="hlt">active</span> regions on the <span class="hlt">auroral</span> oval (as seen with Polar UV imager after projection of the source region along the magnetic field lines down to the ionosphere level). Source region apparent angular sizes based on WDF are compatible with sizes estimated from signal modulation produced by electric antenna system rotation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMSM32B..02L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMSM32B..02L&link_type=ABSTRACT"><span id="translatedtitle">First Satellite Imaging of <span class="hlt">Auroral</span> Pulsations by the Fast <span class="hlt">Auroral</span> Imager on e-POP</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lui, A.; Cogger, L.; Howarth, A. D.; Yau, A. W.</p> <p>2015-12-01</p> <p>We report the first satellite imaging of <span class="hlt">auroral</span> pulsations by the Fast <span class="hlt">Auroral</span> Imager (FAI) onboard the Enhanced Polar Outflow Probe (e-POP) satellite. The near-infrared camera of FAI is capable of providing up to two <span class="hlt">auroral</span> images per second, ideal for investigation of pulsating auroras. The <span class="hlt">auroral</span> pulsations were observed within the <span class="hlt">auroral</span> bulge formed during a substorm interval on 2014 February 19. This first satellite view of these pulsations from FAI reveals that (1) several pulsating <span class="hlt">auroral</span> channels (PACs) occur within the <span class="hlt">auroral</span> bulge, (2) periods of the intensity pulsations span over one decade within the <span class="hlt">auroral</span> bulge, and (3) there is no apparent trend of longer pulsation periods associated with higher latitudes for these PACs. Although PACs resemble in some respect stable pulsating auroras reported previously but they have several important differences in characteristics.PACs are not embedded in or emerging from omega bands or torches and are located at significant distances from the equatorward boundary of the <span class="hlt">auroral</span> oval, unlike the characteristics of stable pulsating auroras.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5915589','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5915589"><span id="translatedtitle"><span class="hlt">Auroral</span> pulsations from ionospheric winds</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nakada, M.P. )</p> <p>1989-11-01</p> <p>The possibility that <span class="hlt">auroral</span> pulsations are due to oscillatory electrical circuits in the ionosphere that are driven by the negative resistance of jet stream winds is examined. For the condenser plates, the highly conducting surfaces above the edges of the jet stream are postulated. The dielectric constant of the plasma between the plates is quite large. The current that is driven perpendicular to and by the jet stream closes along the plates and through Pederson currents in the F region above the stream. This closed loop gives the inductance and resistance for the circuit. Periods of oscillation for this circuit appear to be in the range of Pc 1 to Pc 3. In accord with observations, this circuit appears to be able to limit the brightness of pulsations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.youtube.com/watch?v=4XWw3JHSPpg','SCIGOVIMAGE-NASA'); return false;" href="http://www.youtube.com/watch?v=4XWw3JHSPpg"><span id="translatedtitle">OVATION Prime Model and "Aurorasaurus" <span class="hlt">Auroral</span> Observations</span></a></p> <p><a target="_blank" href="http://www.nasa.gov/multimedia/videogallery/index.html">NASA Video Gallery</a></p> <p></p> <p></p> <p>This video shows the <span class="hlt">auroral</span> oval, as modeled using OVATION Prime (2013), along with citizen science reports collected by the Aurorasaurus project for the St. Patrick’s Day storm over March 17-19, ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770026443','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770026443"><span id="translatedtitle">Electromagnetic plasma wave emissions from the <span class="hlt">auroral</span> field lines</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gurnett, D. A.</p> <p>1977-01-01</p> <p>The most important types of <span class="hlt">auroral</span> radio emissions are reviewed, both from a historical perspective as well as considering the latest results. Particular emphasis is placed on four types of electromagnetic emissions which are directly associated with the plasma on the <span class="hlt">auroral</span> field lines. These emissions are (1) <span class="hlt">auroral</span> hiss, (2) saucers, (3) ELF noise bands, and (4) <span class="hlt">auroral</span> kilometric radiation. Ray tracing and radio direction finding measurements indicate that both the <span class="hlt">auroral</span> hiss and <span class="hlt">auroral</span> kilometric radiation are generated along the <span class="hlt">auroral</span> field lines relatively close to the earth, at radial distances from about 2.5 to 5 R sub e. For the <span class="hlt">auroral</span> hiss the favored mechanism appears to be amplified Cerenkov radiation. For the <span class="hlt">auroral</span> kilometric radiation several mechanisms have been proposed, usually involving the intermediate generation of electrostatic waves by the precipitating electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007EOSTr..88..134H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007EOSTr..88..134H"><span id="translatedtitle">Comment: An Apparent Controversy in <span class="hlt">Auroral</span> Physics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haerendel, Gerhard</p> <p>2007-03-01</p> <p>In his article ``A turning point in <span class="hlt">auroral</span> physics,'' Bryant argued against what he called the `standard' theory of <span class="hlt">auroral</span> acceleration, according to which the electrons ``gain their energy from static electric fields,'' and offered wave acceleration as an alternative. Because of the importance of the process, not only for the aurora borealis but also for other cosmic plasmas, a clarification of this apparent controversy seems to be in place.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140011675','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140011675"><span id="translatedtitle">Characteristics of Extreme <span class="hlt">Auroral</span> Charging Events</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Minow, Joseph I.; Willis, Emily M.; Parker, Linda Neergard</p> <p>2014-01-01</p> <p>The highest level spacecraft charging observed in low Earth orbit (LEO) occurs when spacecraft are exposed to energetic <span class="hlt">auroral</span> electrons. Since <span class="hlt">auroral</span> charging has been identified as a mechanism responsible for on-orbit anomalies and even possible satellite failures it is important to consider extreme <span class="hlt">auroral</span> charging events as design and test environments for spacecraft to be used in high inclination LEO orbits. This paper will report on studies of extreme <span class="hlt">auroral</span> charging events using data from the SSJ/4 and SSJ/5 precipitating electron and ion sensors on the Defense Meteorology Satellite Program (DMSP) satellites. Early studies of DMSP charging to negative potentials =100 V focused on statistics of the electron environment responsible for charging. Later statistical studies of <span class="hlt">auroral</span> charging have generally focused on solar cycle dependence of charging behavior and magnitude of the maximum potential and duration of the charging events. We extend these studies to focus on more detailed investigations of extreme charging event characteristics that are required to evaluate potential threats to spacecraft systems. A collection of example <span class="hlt">auroral</span> charging events is assembled from the DMSP data set using the criteria that "extreme <span class="hlt">auroral</span> charging" is defined as periods with spacecraft negative potentials =400 V. Specific characteristics to be treated include (but are not limited to) maximum and mean potentials, time history of spacecraft potentials through the events, total charging duration and the time potentials exceed voltage thresholds, frame charging/discharging rates, and information on geographic and geomagnetic latitudes at which the events are observed. Finally, we will comment on the implications of these studies for potential <span class="hlt">auroral</span> charging risks to the International Space Station.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM23A2220C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM23A2220C"><span id="translatedtitle">Testing the <span class="hlt">Auroral</span> Current-Voltage Relation in Multiple Arcs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cameron, T. G.; Knudsen, D. J.; Cully, C. M.</p> <p>2013-12-01</p> <p>The well-known current-voltage relation within <span class="hlt">auroral</span> inverted-V regions [Knight, Planet. Space Sci., 21, 741, 1973] predicts current carried by an <span class="hlt">auroral</span> flux tube given the total potential drop between a plasma-sheet source region and the ionosphere. Numerous previous studies have tested this relation using spacecraft that traverse <span class="hlt">auroral</span> arcs at low (ionospheric) or mid altitudes. Typically, the potential drop is estimated at the peak of the inverted-V, and field-aligned current is estimated from magnetometer data; statistical information is then gathered over many arc crossings that occur over a wide range of source conditions. In this study we use electron data from the FAST satellite to examine the current-voltage relation in multiple arc sets, in which the key source parameters (plasma sheet density and temperature) are presumed to be identical. We argue that this approach provides a more sensitive test of the Knight relation, and we seek to explain remaining variability with factors other than source variability. This study is supported by a grant from the Natural Sciences and Engineering <span class="hlt">Research</span> Council of Canada.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7296304','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7296304"><span id="translatedtitle">High Frequency <span class="hlt">Active</span> <span class="hlt">Auroral</span> <span class="hlt">Research</span> Program (HAARP) imager. Final report, 29 August 1991-29 August 1993</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lance, C.; Eather, R.</p> <p>1993-09-30</p> <p>A low-light-level monochromatic imaging system was designed and fabricated which was optimized to detect and record optical emissions associated with high-power rf heating of the ionosphere. The instrument is capable of detecting very low intensities, of the order of 1 Rayleigh, from typical ionospheric atomic and molecular emissions. This is achieved through co-adding of ON images during heater pulses and subtraction of OFF (background) images between pulses. Images can be displayed and analyzed in real time and stored in optical disc for later analysis. Full image processing software is provided which was customized for this application and uses menu or mouse user interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840045421&hterms=isis+map&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Disis%2Bmap','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840045421&hterms=isis+map&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Disis%2Bmap"><span id="translatedtitle"><span class="hlt">Auroral</span> kilometric radiation/aurora correlation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benson, R. F.; Akasofu, S.-I.</p> <p>1984-01-01</p> <p><span class="hlt">Auroral</span> kilometric radiation (AKR) observations from the ISIS 1 topside sounder receiver were compared with visual <span class="hlt">auroral</span> observations from the network of Alaskan all-sky camera stations. The goal was to relate AKR source region encounters to specific <span class="hlt">auroral</span> forms on the same magnetic field line. Thirty-eight simultaneous data sets were identified and analyzed. In general, intense AKR was associated with bright <span class="hlt">auroral</span> arcs and conditions of weak or no AKR corresponded to times when either no aurora or only a faint arc or weak diffuse aurora were observed. Five cases, when both intense AKR and bright visual aurora were present, were analyzed in detail. Complete electron density N sub e contours, from the satellite altitude down to the F region ionization peak, were obtained along N-S traversals of the AKR source region. In addition, the ISIS 1 orbital tracks were projected down the magnetic field lines to the <span class="hlt">auroral</span> altitude and compared to <span class="hlt">auroral</span> features on a map derived from the all sky camera images. Density cavities (regions where N sub e 100/cu cm) were encountered on each of these passes. Previously announced in STAR as N83-27516</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830019245','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830019245"><span id="translatedtitle"><span class="hlt">Auroral</span> kilometric radiation/aurora correlation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benson, R. F.; Akasofu, S. I.</p> <p>1983-01-01</p> <p><span class="hlt">Auroral</span> kilometric radiation (AKR) observations from the ISIS 1 topside sounder receiver were compared with visual <span class="hlt">auroral</span> observations from the network of Alaskan all-sky camera stations. The goal was to relate AKR source region encounters to specific <span class="hlt">auroral</span> forms on the same magnetic field line. Thirty-eight simultaneous data sets were identified and analyzed. In general, intense AKR was associated with bright <span class="hlt">auroral</span> arcs and conditions of weak or no AKR corresponded to times when either no aurora or only a faint arc or weak diffuse aurora were observed. Five cases, when both intense AKR and bright visual aurora were present, were analyzed in detail. Complete electron density N sub e contours, from the satellite altitude down to the F region ionization peak, were obtained along N-S traversals of the AKR source region. In addition, the ISIS 1 orbital tracks were projected down the magnetic field lines to the <span class="hlt">auroral</span> altitude and compared to <span class="hlt">auroral</span> features on a map derived from the all sky camera images. Density cavities (regions where N sub e 100/cu cm) were encountered on each of these passes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PhDT.......103H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PhDT.......103H"><span id="translatedtitle"><span class="hlt">Auroral</span> effects on meteoric metals in the upper atmosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heinselman, Craig James</p> <p>1999-12-01</p> <p>Meteors deposit many tons of material into Earth's upper atmosphere each day. The physics and chemistry of meteoric metals in the atmosphere have long been <span class="hlt">active</span> topics of study, but sophisticated models have emerged just recently of the gas-phase chemical reactions that affect the evolution of the state of these metals. At high latitudes, this portion of the upper atmosphere is also shared by the aurora borealis, or northern lights, which dramatically alter the properties of the background plasma. This thesis concerns coupled chemical models and one- dimensional dynamical models that were developed to investigate the effects of <span class="hlt">auroral</span> ionization on the time evolution of meteoric iron and sodium elements and compounds in the upper atmosphere. These models are used to show that aurorae can result in rapid ionization of recently deposited iron and sodium, with time constants on the order of 15 minutes. The models are also used to investigate the influence of aurorae on the background iron and sodium layers. Because of the nominal altitude of the neutral iron layer, aurorae will not normally have a measurable impact on that constituent. For sodium, on the other hand, the impact is more significant but highly dependent on the chemical makeup of the <span class="hlt">aurorally</span> produced ions. For either case, sporadic neutral atom layers at <span class="hlt">auroral</span> altitudes are significantly affected. A case study of radar and lidar measurements from the Sondrestrom Facility in Greenland is used to test the sodium model. Results are presented which are consistent with the model predictions of the effects of the <span class="hlt">aurorally</span> enhanced ionization. For this specific case, evidence is also presented to support a gas-phase chemical mechanism for the formation of a thin the formation of a thin sporadic sodium layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFMSM22A0562T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFMSM22A0562T"><span id="translatedtitle">Composition of <span class="hlt">Auroral</span> Polar Cap Boundary Ion Conics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tung, Y.; Carlson, C. W.; McFadden, J. P.; Parks, G. K.; Lund, E. J.; Eriksson, S.; Ergun, R. E.</p> <p>2002-12-01</p> <p>Ion conics have frequently been observed by FAST on the <span class="hlt">auroral</span> polar cap boundary, which we have defined as where the ion energy flux sharply drops off. These polar cap boundary (PCB) ion conics are particularly prevalent in the nightside sector near midnight. Of medium energies (100 eV to 1 keV), these ion conics are characterized by intense number fluxes and often constitute the majority of the outflow from the nightside <span class="hlt">auroral</span> oval. An earlier study has reported that the PCB ion outflow consisted predominantly of H+ and He+, while a separate study presented data that showed PCB ion conics that consisted primarily of oxygen ions. Possible explanations for the composition change include solar cycle variation or seasonal variation. We will explore through a systematic consideration of FAST orbits from 1997 through 2000 the change in composition of PCB ion conics. Since neither the solar cycle nor the seasons alone seem to explain the variation in ion composition of the PCB ion conics, we will consider alternative possibilities such as convection, IMF dependence, or <span class="hlt">auroral</span> <span class="hlt">activity</span> level and history.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016BrJPh..46...97O&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016BrJPh..46...97O&link_type=ABSTRACT"><span id="translatedtitle">Effects of Interplanetary Shock Inclinations on Nightside <span class="hlt">Auroral</span> Power Intensity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oliveira, D. M.; Raeder, J.; Tsurutani, B. T.; Gjerloev, J. W.</p> <p>2016-02-01</p> <p>We derive fast forward interplanetary (IP) shock speeds and impact angles to study the geoeffectiveness of 461 IP shocks that occurred from January 1995 to December 2013 using ACE and Wind spacecraft data. The geomagnetic <span class="hlt">activity</span> is inferred from the SuperMAG project data. SuperMAG is a large chain which employs more than 300 ground stations to compute enhanced versions of the traditional geomagnetic indices. The SuperMAG <span class="hlt">auroral</span> electroject SME index, an enhanced version of the traditional AE index, is used as an <span class="hlt">auroral</span> power (AP) indicator. AP intensity jumps triggered by shock impacts are correlated with both shock speed and impact angle. It is found that high AP intensity events typically occur when high speed IP shocks impact the Earth's magnetosphere with the shock normal almost parallel to the Sun-Earth line. This result suggests that symmetric and strong magnetospheric compression leads to favorable conditions for intense <span class="hlt">auroral</span> power release, as shown previously by simulations and observations. Some potential mechanisms will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003xmm..pres...31.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003xmm..pres...31."><span id="translatedtitle">ESA's Cluster solved an <span class="hlt">auroral</span> puzzle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p></p> <p>2003-05-01</p> <p> investigation at the University of California, Berkeley, United States, now looks forward to a new way of studying the Earth’s protective shield. He says, “This result has opened up a new area of <span class="hlt">research</span>. We can now watch dayside proton aurorae and use those observations to know where and how the cracks in the magnetic field are formed and how long the cracks remain open. That makes it a powerful tool to study the entry of the solar wind into the Earth’s magnetosphere.” The Earth’s interaction with the Sun is a current focus of scientific attention because of its importance in knowing how the Sun affects the Earth, most notably our climate. Also, while not immediately dangerous to us on Earth, it is also important for quantifying the danger to satellites, which can be damaged or destroyed by powerful solar flares. Note to Editors: Proton aurorae were globally imaged for the first time by NASA’s IMAGE spacecraft. The images revealed the presence of the ‘dayside proton <span class="hlt">auroral</span> spots’. By a fortunate coincidence, IMAGE and Cluster both spotted the event on 18 March 2002. Combining with IMAGE’s observations, Cluster made it possible to establish the ground truth of the phenomenon. The paper on these results, Simultaneous Cluster and IMAGE Observations of Cusp Reconnection and <span class="hlt">Auroral</span> Spot for Northward IMF by Tai Phan and 24 other authors will be published in Geophysical <span class="hlt">Research</span> Letters, 21 May 2003, Vol. 30, No. 10. The principal investigators responsible for the instruments that made these results possible are: Henri Rème of CESR/Toulouse, France (Cluster Proton Detectors), Andre Balogh of Imperial College, London, United Kingdom (Cluster Magnetic Field Instrument) and Stephen Mende of University of California, Berkeley, United States (IMAGE/FUV). More about Cluster ESA’s Cluster is a collection of four spacecraft, launched on two Russian rockets during the summer of 2000. They are now flying in formation around the Earth, relaying the most detailed ever</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRA..118..685I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRA..118..685I"><span id="translatedtitle">The Heppner-Maynard Boundary measured by SuperDARN as a proxy for the latitude of the <span class="hlt">auroral</span> oval</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Imber, S. M.; Milan, S. E.; Lester, M.</p> <p>2013-02-01</p> <p>We present a statistical study relating the latitude of the <span class="hlt">auroral</span> oval measured by the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) SI-12 proton <span class="hlt">auroral</span> camera to that of the Heppner-Maynard Boundary (HMB) determined from Super Dual <span class="hlt">Auroral</span> Radar Network (SuperDARN) data during the period 2000-2002. The HMB represents the latitudinal extent of the ionospheric convection pattern. The oval latitude from the proton <span class="hlt">auroral</span> images is determined using the method of Milan et al. (2009a), which fits a circle centered on a point 2° duskward and 5° antisunward of the magnetic pole. The <span class="hlt">auroral</span> latitude at midnight is determined for those images where the concurrent SuperDARN northern hemisphere maps contain more than 200 data points such that the HMB is well-defined. The statistical study comprises over 198,000 two-minute intervals, and we find that the HMB is located on average 2.2° equatorward of the proton <span class="hlt">auroral</span> latitude. A superposed epoch analysis of over 2500 substorms suggests that the separation between the HMB and the oval latitude increases slightly during periods of high geomagnetic <span class="hlt">activity</span>. We suggest that during intervals where there are no <span class="hlt">auroral</span> images available, the HMB latitude and motion could be used as a proxy for that of the aurora, and therefore provide information about motions of the open/closed field line boundary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040110876&hterms=Magnetosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DMagnetosphere','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040110876&hterms=Magnetosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DMagnetosphere"><span id="translatedtitle">Magnetosphere-Ionosphere Coupling in the <span class="hlt">Auroral</span> Zone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schriver, David</p> <p>2004-01-01</p> <p>The visual light display at high latitudes referred to as the aurora fascinates casual observers and <span class="hlt">researchers</span> alike. The natural question is what causes the aurora? We know that energized electrons streaming along the Earth's ambient magnetic field and colliding with atmospheric particles produce aurora. We do not know for certain, however, how these electrons are accelerated to high energies primarily in the field-aligned direction toward the Earth, or what the drivers of this acceleration are. As such, the goal of this Guest Investigator <span class="hlt">research</span> project was to examine the physical processes that can cause field-aligned acceleration of plasma particles in the <span class="hlt">auroral</span> region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AGUFM.P42B..03L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AGUFM.P42B..03L&link_type=ABSTRACT"><span id="translatedtitle">Polarisation of the <span class="hlt">auroral</span> red line in the Earth's upper atmosphere: a review (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lamy, H.; Barthelemy, M.; Lilensten, J.; Bommier, V.; Simon Wedlund, C.</p> <p>2013-12-01</p> <p>Polarisation of light is a key observable to provide information about asymmetry or anisotropy within a radiative source. Polarimetry of <span class="hlt">auroral</span> emission lines in the Earth's upper atmosphere has been overlooked for decades. However, the bright red <span class="hlt">auroral</span> line (6300Å) produced by collisional impact with electrons precipitating along magnetic field lines is a good candidate to search for polarisation. This problem was investigated recently with observations obtained by Lilensten et al (2008), Barthélemy et al (2011) and Lilensten et al (2013) with a photopolarimeter. Analysis of the data indicates that the red <span class="hlt">auroral</span> emission line is polarised at a level of a few percent. The results are compared to theoretical predictions of Bommier et al (2011) that were obtained for a collimated beam. The comparison suggests the existence of depolarization processes whose origin will be discussed. A new dedicated spectropolarimeter currently under development will also be presented. This instrument will cover the optical spectrum from approximately 400 to 700 nm providing simultaneously the polarisation of the red line and of other interesting <span class="hlt">auroral</span> emission lines such as N2+ 1NG (4278Å), other N2 bands, etc... The importance of these polarisation measurements in the context of upper atmosphere modelling and geomagnetic <span class="hlt">activity</span> will be discussed. Lilensten, J. et al, Polarization in aurorae: A new dimension for space environments studies, Geophys. Res. Lett., 26, 269, 2008 Barthélemy M. et al, Polarisation in the <span class="hlt">auroral</span> red line during coordinated EISCAT Svalbard Radar/optical experiments, Annales Geophysicae, Volume 29, Issue 6, 2011, 1101-1112, 2011. Bommier V. et al, The Theoretical Impact Polarization of the O I 6300 Å Red Line of Earth <span class="hlt">Auror</span>æ, Annales Geophysicae, Volume 29, Issue 1, 2011, 71-79, 2011 Lilensten, J. et al, The thermospheric <span class="hlt">auroral</span> red line polarization: confirmation of detection and first quantitative analysis, Journal of Space Weather and Space</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.4055T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.4055T"><span id="translatedtitle">Variation of Jupiter's aurora observed by Hisaki/EXCEED: 2. Estimations of <span class="hlt">auroral</span> parameters and magnetospheric dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tao, Chihiro; Kimura, Tomoki; Badman, Sarah V.; André, Nicolas; Tsuchiya, Fuminori; Murakami, Go; Yoshioka, Kazuo; Yoshikawa, Ichiro; Yamazaki, Atsushi; Fujimoto, Masaki</p> <p>2016-05-01</p> <p>Jupiter's <span class="hlt">auroral</span> parameters are estimated from observations by a spectrometer EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) on board Japanese Aerospace Exploration Agency's Earth-orbiting planetary space telescope Hisaki. EXCEED provides continuous <span class="hlt">auroral</span> spectra covering the wavelength range over 80-148 nm from the whole northern polar region. The <span class="hlt">auroral</span> electron energy is estimated using a hydrocarbon color ratio adopted for the wavelength range of EXCEED, and the emission power in the long wavelength range 138.5-144.8 nm is used as an indicator of total emitted power before hydrocarbon absorption and <span class="hlt">auroral</span> electron energy flux. The quasi-continuous observations by Hisaki provide the <span class="hlt">auroral</span> electron parameters and their relation under different <span class="hlt">auroral</span> <span class="hlt">activity</span> levels. Short- (within < one planetary rotation) and long-term (> one planetary rotation) enhancements of <span class="hlt">auroral</span> power accompany increases of the electron number flux rather than the electron energy variations. The relationships between the <span class="hlt">auroral</span> electron energy (~70-400 keV) and flux (1026-1027/s, 0.08-0.9 μA/m2) estimated from the observations over a 40 day interval are in agreement with field-aligned acceleration theory when incorporating probable magnetospheric parameters. Applying the electron acceleration theory to each observation point, we explore the magnetospheric source plasma variation during these power-enhanced events. Possible scenarios to explain the derived variations are (i) an adiabatic variation of the magnetospheric plasma under a magnetospheric compression and/or plasma injection, and (ii) a change of the dominant <span class="hlt">auroral</span> component from the main emission (main aurora) to the emission at the open-closed boundary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5361710','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5361710"><span id="translatedtitle"><span class="hlt">Auroral</span> resonance line radiative transfer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gladstone, G.R. )</p> <p>1992-02-01</p> <p>A model is developed for simulating the two-dimensional radiative transfer of resonance line emissions in auroras. The method of solution utilizes Fourier decomposition of the horizontal dependence in the intensity field so that the two-dimensional problem becomes a set of one-dimensional problems having different horizontal wavenumbers. The individual one-dimensional problems are solved for using a Feautrier-type solution of the differential-integral form of the radiative transfer equation. In the limit as the horizontal wavenumber becomes much larger than the local line-center extinction coefficient, the scattering integral becomes considerably simplified, and the final source function is evaluated in closed form. The two-dimensional aspects of the model are tested against results for nonresonance radiative transfer studies, and the resonance line part of the model is tested against results of existing plane-parallel resonance line radiative transfer codes. Finally, the model is used to simulate the intensity field of O{sub I} 1,304{angstrom} for hard and soft auroras of various Gaussian horizontal widths. The results demonstrate the importance of considering the effects of two-dimensional radiative transfer when analyzing <span class="hlt">auroral</span> resonance line data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16..472N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16..472N"><span id="translatedtitle">Quasi-Stationary Global <span class="hlt">Auroral</span> Ionospheric Model: E-layer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nikolaeva, Vera; Gordeev, Evgeny; Kotikov, Andrey; Makarova, Ludmila; Shirochkov, Aleksander</p> <p>2014-05-01</p> <p>E-layer <span class="hlt">Auroral</span> Ionospheric Model (E-AIM) is developed to provide temporal and spatial density distribution of the main ionosphere neutral species (NO, N(4S),N(2D)), and ions (N2+, NO+,O2+,O+) in the altitude range from 90 to 150 km. NRLMSISE-00 model [Picone et al., JGR 2003] is used for neutral atmosphere content and temperature determination, that is the input for the E-AIM model. The E-AIM model based on chemical equilibrium state in E-layer that reaches in chemical reactions between ionospheric species considering solar radiation ionization source, superposed with sporadic precipitation of magnetospheric electrons. The chemical equilibrium state in each location under specific solar and geomagnetic <span class="hlt">activity</span> conditions reaches during numerical solution of the continuity equations for the neutrals and ions using the high-performance Gear method [Gear, 1971] for ordinary differential equation (ODE) systems. Applying the Gear method for solving stiff ODE system strongly reduce the computation time and machine resources comparing to widely used methods and provide an opportunity to calculate the global spatial E-layer ion content distribution. In contrast to the mid-latitude ionosphere, structure and dynamics of the <span class="hlt">auroral</span> zone ionosphere (φ ≡ 60-75° MLat) associated not only with shortwave solar radiation. Precipitating magnetospheric particle flux is the most important ionization source and is the main cause of E-layer disturbances. Precipitated electrons with initial energies of 1 - 30 keV influence the <span class="hlt">auroral</span> ionosphere E-layer. E-AIM model can estimate ionization rate corresponds to <span class="hlt">auroral</span> electron precipitation in two different ways: 1. with direct electron flux satellite data; 2. with differential energy spectrum reconstructed from OVATION-Prime empirical model [Newell, JGR 2009] average values, that allows to estimate ionosphere ion content for any time and location in the <span class="hlt">auroral</span> zone. Comparison of E-AIM results with direct ionospheric observations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhDT........68M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhDT........68M"><span id="translatedtitle">Characteristics of dayside <span class="hlt">auroral</span> displays in relation to magnetospheric processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Minow, Joseph I.</p> <p>1997-09-01</p> <p>The use of dayside aurorae as a ground based monitor of magnetopause <span class="hlt">activity</span> is explored in this thesis. The origin of diffuse (OI) 630.0 nm emissions in the midday <span class="hlt">auroral</span> oval is considered first. Analysis of low altitude satellite records of precipitating charged particles within the cusp show an unstructured electron component that will produce a 0.5-1 kR 630.0 nm emission throughout the cusp. Distribution of the electrons is controlled by the requirement of charge neutrality in the cusp, predicting a diffuse 630.0 nm background even if the magnetosheath plasma is introduced into the magnetosphere in discrete merging events. Cusp electron fluxes also contain a structured component characterized by enhancements in the electron energy and energy flux over background values in narrow regions a few 10's of kilometers in width. These structured features are identified as the source of the transient midday arcs. An <span class="hlt">auroral</span> model is developed to study the morphology of (OI) 630.0 nm <span class="hlt">auroral</span> emissions produced by the transient arcs. The model demonstrates that a diffuse 630.0 nm background emission is produced by transient arcs due to the long lifetime of the O(1D) state. Two sources of diffuse 630.0 nm background emissions exist in the cusp which may originate in discrete merging events. The conclusion is that persistent 630.0 nm emissions cannot be interpreted as prima facie evidence for continuous particle transport from the magnetosheath across the magnetopause boundary and into the polar cusp. The second subject that is considered is the analysis of temporal and spatial variations of the diffuse 557.7 nm pulsating aurora in relation to the 630.0 nm dominated transient aurora. Temporal variations at the poleward boundary of the diffuse 557.7 nm aurora correlate with the formation of the 630.0 nm transient aurorae suggesting that the two events are related. The character of the <span class="hlt">auroral</span> variations is consistent with the behavior of particle populations reported</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JGRA..11310215A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JGRA..11310215A"><span id="translatedtitle">Stochastic modeling of the <span class="hlt">auroral</span> electrojet index</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anh, V. V.; Yong, J. M.; Yu, Z. G.</p> <p>2008-10-01</p> <p>Substorms are often identified by bursts of <span class="hlt">activities</span> in the magnetosphere-ionosphere system characterized by the <span class="hlt">auroral</span> electrojet (AE) index. The highly complex nature of substorm-related bursts suggests that a stochastic approach would be needed. Stochastic models including fractional Brownian motion, linear fractional stable motion, Fokker-Planck equation and Itô-type stochastic differential equation have been suggested to model the AE index. This paper provides a stochastic model for the AE in the form of fractional stochastic differential equation. The long memory of the AE time series is represented by a fractional derivative, while its bursty behavior is modeled by a Lévy noise with inverse Gaussian marginal distribution. The equation has the form of the classical Stokes-Boussinesq-Basset equation of motion for a spherical particle in a fluid with retarded viscosity. Parameter estimation and approximation schemes are detailed for the simulation of the equation. The fractional order of the equation conforms with the previous finding that the fluctuations of the magnetosphere-ionosphere system as seen in the AE reflect the fluctuations in the solar wind: they both possess the same extent of long-range dependence. The introduction of a fractional derivative term into the equation to capture the extent of long-range dependence together with an inverse Gaussian noise input describe the right amount of intermittency inherent in the AE data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMED53B0852C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMED53B0852C"><span id="translatedtitle">The <span class="hlt">Auroral</span> Zone: A citizen science project to classify <span class="hlt">auroral</span> imaging data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chaddock, D.; Spanswick, E.; Gillies, D. M.; Quinney, A.; Donovan, E.; Murray, M. S.</p> <p>2015-12-01</p> <p>Currently, over 40 million images of the aurora have been recorded by University of Calgary all-sky imagers. Analysis of these images is an important and crucial step in the advancement of <span class="hlt">auroral</span> physics. The number of images waiting to be analyzed is expected to increase dramatically with the introduction of TREx (Transition Region Explorer), a new high resolution imaging network set to be deployed in late 2016. In order to classify large amounts of images in a short period of time, we have designed a citizen science project aimed at engaging the general public in <span class="hlt">auroral</span> science, called "The <span class="hlt">Auroral</span> Zone". This project facilitates a symbiotic relationship between the scientific community and the general public. Using the data from this website, a large database of classified <span class="hlt">auroral</span> images will be created and then used for future analysis by the scientific community. In exchange, the general public can learn about the aurora and contribute to <span class="hlt">auroral</span> physics in a tangible way. The ultimate aim of this project is to create an ever expanding database of all-sky images classified by arc type (i.e. single arc, diffuse aurora, multiple arc, etc.) and filtered for adverse viewing conditions (i.e. snow, rain, light pollution, etc). We aim to introduce "The <span class="hlt">Auroral</span> Zone" into the school systems to interest young scientists in the spectacular natural phenomenon that defines the Canadian North. "The <span class="hlt">Auroral</span> Zone" is a collaborative project between the University of Calgary, Canadian Space Agency, AuroraMAX, and Aurorasaurus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4681424','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4681424"><span id="translatedtitle">First light from a kilometer-baseline Scintillation <span class="hlt">Auroral</span> GPS Array</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Datta-Barua, S; Su, Y; Deshpande, K; Miladinovich, D; Bust, G S; Hampton, D; Crowley, G</p> <p>2015-01-01</p> <p>We introduce and analyze the first data from an array of closely spaced Global Positioning System (GPS) scintillation receivers established in the <span class="hlt">auroral</span> zone in late 2013 to measure spatial and temporal variations in L band signals at 100–1000 m and subsecond scales. The seven receivers of the Scintillation <span class="hlt">Auroral</span> GPS Array (SAGA) are sited at Poker Flat <span class="hlt">Research</span> Range, Alaska. The receivers produce 100 s scintillation indices and 100 Hz carrier phase and raw in-phase and quadrature-phase samples. SAGA is the largest existing array with baseline lengths of the ionospheric diffractive Fresnel scale at L band. With an initial array of five receivers, we identify a period of simultaneous amplitude and phase scintillation. We compare SAGA power and phase data with collocated 630.0 nm all-sky images of an <span class="hlt">auroral</span> arc and incoherent scatter radar electron precipitation measurements, to illustrate how SAGA can be used in multi-instrument observations for subkilometer-scale studies. Key Points A seven-receiver Scintillation <span class="hlt">Auroral</span> GPS Array (SAGA) is now at Poker Flat, Alaska SAGA is the largest subkilometer array to enable phase/irregularities studies Simultaneous scintillation, <span class="hlt">auroral</span> arc, and electron precipitation are observed PMID:26709318</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E2283N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E2283N"><span id="translatedtitle">The Ionospheric Model Adaptation to the <span class="hlt">Auroral</span> Latitudes With UHF EISCAT Radar and Tromso Magnetometer Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nikolaeva, Vera; Gordeev, Evgeny; Kotikov, Andrey</p> <p></p> <p>E-layer <span class="hlt">Auroral</span> Ionosphere Model (E-AIM) developed in Arctic and Antarctic <span class="hlt">Research</span> Institute can provide temporal and spatial distribution of the main ionosphere parameters: ion and electron density distribution in the altitude range from 90 to 150 km. The statistical study of E-layer electron density dependence on substorm <span class="hlt">activity</span> was made to improve model results in high latitudes. About fifty substorms were included to the data analysis. Particular attention was paid to the dynamics of magnetic disturbances and ionospheric parameters measured by the radar. Correlation of electron density values measured by the UHF EISCAT incoherent scattering radar with geomagnetic indices was determined. Applicability of geomagnetic indices as input parameters of the local E-AIM model was estimated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA13A2142G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA13A2142G"><span id="translatedtitle">Modulation of <span class="hlt">auroral</span> electrojet currents using dual HF beams with ELF phase offset</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Golkowski, M.; Cohen, M.; Moore, R. C.</p> <p>2012-12-01</p> <p>The modulation of naturally occuring ionospheric currents with high power radio waves in the high frequency (HF, 3-10 MHz) band is a well known technique for generation of extremely low frequency (ELF, 3-3000 Hz) and very low frequency (VLF, 3-30 kHz) waves. We use the heating facility of the High Frequency <span class="hlt">Active</span> <span class="hlt">Auroral</span> <span class="hlt">Research</span> Program (HAARP) to investigate the effect of using dual HF beams with an ELF/VLF phase offset between the modulation waveforms. Experiments with offset HF beams confirm the model of independent ELF/VLF sources. Experiments with co-located HF beams exhibit interaction between the first and second harmonics of the modulated tones when square and sine wave modulation waveforms are employed. Using ELF/VLF phase offsets for co-loacted beams is also shown to be a potential diagnostic for the D-region ionospheric profile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AnGeo..21.1847P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AnGeo..21.1847P"><span id="translatedtitle">On the occurrence and motion of decametre-scale irregularities in the sub-<span class="hlt">auroral</span>, <span class="hlt">auroral</span>, and polar cap ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parkinson, M. L.; Devlin, J. C.; Ye, H.; Waters, C. L.; Dyson, P. L.; Breed, A. M.; Morris, R. J.</p> <p>2003-08-01</p> <p>The statistical occurrence of decametre-scale ionospheric irregularities, average line-of-sight (LOS) Doppler velocity, and Doppler spectral width in the sub-<span class="hlt">auroral</span>, <span class="hlt">auroral</span>, and polar cap ionosphere ( - 57°L</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19810051634&hterms=Particle+accelerators&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2528Particle%2Baccelerators%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19810051634&hterms=Particle+accelerators&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2528Particle%2Baccelerators%2529"><span id="translatedtitle">Very low frequency waves stimulated by an electron accelerator in the <span class="hlt">auroral</span> ionosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Holtet, J. A.; Pran, B. K.; Egeland, A.; Grandal, B.; Jacobsen, T. A.; Maehlum, B. N.; Troim, J.</p> <p>1981-01-01</p> <p>The sounding rocket, Polar 5, carrying a 10 keV electron accelerator in a mother-daughter configuration and other diagnostic instruments, was launched into a slightly disturbed ionosphere with weak <span class="hlt">auroral</span> <span class="hlt">activity</span> on February 1, 1976 from Northern Norway to study VLF wave phenomena. The rocket trajectory crossed two <span class="hlt">auroral</span> regions: one, between 86 and 111 s flight time, and a secondary region between 230 and 330 s. The daughter, carrying the accelerator, was separated axially from the mother in a forward direction at an altitude of 90 km. The VLF experiment, carried by the mother payload, recorded both electromagnetic and electrostatic waves. The receiving antenna was an electric dipole, 0.3 m tip-to-tip, oriented 90 degrees to the rocket spin axis. The onboard particle detector recorded increased electron fluxes in the two <span class="hlt">auroral</span> regions. A double peaked structure was observed in the fluxes of 4-5 and 12-27 keV electrons within the northern <span class="hlt">auroral</span> form. The number density of thermal plasma varied during the flight, with maximum density within the main <span class="hlt">auroral</span> region. To the north of this aurora a slow, steady decrease in the density was observed, with no enhancement in the region of the second aurora.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870052848&hterms=average+wind+speeds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Daverage%2Bwind%2Bspeeds','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870052848&hterms=average+wind+speeds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Daverage%2Bwind%2Bspeeds"><span id="translatedtitle">Global <span class="hlt">auroral</span> responses to magnetospheric compressions by shocks in the solar wind - Two case studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Craven, J. D.; Frank, L. A.; Russell, C. T.; Smith, E. J.; Lepping, R. P.</p> <p>1986-01-01</p> <p>The global <span class="hlt">auroral</span> responses to shocks in the solar wind at earth were studied. The z-component of the interplanetary magnetic field, Bz, is negative ahead and behind the first shock and positive for the second case. A sudden-commencement geomagnetic storm develops in each case, with maximum D sub st 190 nT. An immediate <span class="hlt">auroral</span> response is detected at all longitudes around the <span class="hlt">auroral</span> oval, in which <span class="hlt">auroral</span> luminosities increase by a factor of 2 to 3 with the first samples after each sudden commencement. The time delay in obtaining the first sample varies with local time from approx. 1 to 19 mins. No other significant variations in the aurora are associated with the immediate response. Beginning approx. 30 mins after each sudden commencement, the aurora becomes <span class="hlt">active</span> and displays significant variations in its luminosity and spatial distribution. For Bz 0 an intense substorm develops. A sun-aligned transpolar arc forms when Bz 0, appearing first at local midnight as a polar arc and then lengthening sunward from the <span class="hlt">auroral</span> oval across the polar cap to noon at an average speed of approx. 1 km/sec.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860007325','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860007325"><span id="translatedtitle">Global <span class="hlt">auroral</span> responses to magnetospheric compressions by shocks in the solar wind: Two case studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Craven, J. D.; Frank, L. A.; Russell, C. T.; Smith, E. J.; Lepping, R. P.</p> <p>1985-01-01</p> <p>The global <span class="hlt">auroral</span> responses to shocks in the solar wind at Earth were studied. The z-component of the interplanetary magnetic field, Bz, is negative ahead and behind the first shock and positive for the second case. A sudden-commencement geomagnetic storm develops in each case, with maximum D sub st 190 nT. An immediate <span class="hlt">auroral</span> response is detected at all longitudes around the <span class="hlt">auroral</span> oval, in which <span class="hlt">auroral</span> luminosities increase by a factor of 2 to 3 with the first samples after each sudden commencement. The time delay in obtaining the first sample varies with local time from approx. 1 to 18 mins. No other significant variations in the aurora are associated with the immediate response. Beginning approx. 30 mins after each sudden commencement, the aurora becomes <span class="hlt">active</span> and displays significant variations in its luminosity and spatial distribution. For Bz 0 an intense substorm develops. A sun-aligned transpolar arc forms when Bz 0, appearing first at local midnight as a polar arc and then lengthening sunward from the <span class="hlt">auroral</span> oval across the polar cap to noon at an average speed of approx. 1 km/sec.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSM53B..08S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSM53B..08S"><span id="translatedtitle">Cluster Observations of the <span class="hlt">Auroral</span> Acceleration Region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sadeghi, S.; Marklund, G.; Karlsson, R.; Lindqvist, P.; Li, B.; Nilsson, H.; Marghitu, O.; Fazakerley, A. N.; Lucek, E. A.</p> <p>2011-12-01</p> <p>We present results from Cluster satellite multi-point event studies from the <span class="hlt">auroral</span> acceleration region (AAR). Electric potential structures associated with inverted-V aurora are investigated using electric field, magnetic field, ion and electron data from the Cluster spacecraft, crossing the <span class="hlt">auroral</span> acceleration region (AAR) at different altitudes above the <span class="hlt">auroral</span> oval. The spatial and temporal development of the acceleration structures is studied, given the magnetic conjunction opportunity and the short time-difference between the Cluster spacecraft crossings. The configuration allowed for estimating the characteristic times of development for the structures and estimating the parallel electric field and potential drop. For one of the negative potential structures, a growth time of 40 s and stability for more than one minute was observed and an average parallel electric field was estimated (~ 0.56 mV/m, between 1.13 and 1.3 RE of altitude).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820030700&hterms=soliton&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsoliton','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820030700&hterms=soliton&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsoliton"><span id="translatedtitle"><span class="hlt">Auroral</span> kilometric radiation - A theoretical review</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Grabbe, C. L.</p> <p>1981-01-01</p> <p><span class="hlt">Auroral</span> kilometric radiation (AKR) is a high-density radio wave radiation in the frequency band from 50 to 750 kHz, with a peak around 250 kHz, that has been observed emanating from the <span class="hlt">auroral</span> zone. In connection with its low frequency, the radiation can not penetrate through the ionosphere to earth, so all observations have been made by satellite. The AKR is closely correlated with the occurrence of discrete <span class="hlt">auroral</span> arcs, which are believed to be generated by intense inverted V electron precipitation bands. A review is presented of several theories which have been proposed to explain the observed AKR. Attention is given to the conversion of electron cyclotron wave to O mode, the coherent amplification of gyroemission by velocity space instabilities, beam-driven electromagnetic instability via low-frequency turbulence, soliton radiation, loss cone instability, nonlinear beating of electrostatic waves, and the beam amplification of electromagnetic wave via coherent EIC density fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19800055153&hterms=Valenzuela&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DValenzuela','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19800055153&hterms=Valenzuela&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DValenzuela"><span id="translatedtitle">Electric fields in the dayside <span class="hlt">auroral</span> oval</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jorgensen, T. S.; Mikkelsen, I. S.; Lassen, K.; Haerendel, G.; Reiger, E.; Valenzuela, A.; Mozer, F. S.; Temerin, M.; Holback, B.; Bjoern, L.</p> <p>1980-01-01</p> <p>The results from four independent electric field experiments flown on three Black Brant 4 rockets in the forenoon dayside <span class="hlt">auroral</span> oval in December 1974 and January 1975 are correlated with ground-based observations and rocket particle data. The electric field varied from zero to 150 mV/m. The predominant plasma convection was toward noon along the <span class="hlt">auroral</span> oval with a smaller component directed toward the polar cap. In one case, however, a reversal occurred within the oval with plasma convection away from noon. Comparisons with magnetometer data indicate that in the dayside <span class="hlt">auroral</span> oval, Hall currents sometimes are responsible for magnetic fluctuations observed on the ground. Comparisons with particle data show that the magnitude of the electric fields is inversely correlated with the electron energy flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17842831','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17842831"><span id="translatedtitle"><span class="hlt">Auroral</span> Phenomena: Associated with auroras in complex ways are an extraordinary number of other physical phenomena.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>O'brien, B J</p> <p>1965-04-23</p> <p>The array of <span class="hlt">auroral</span> phenomena involves all the basic types of physical phenomena: heat, light, sound, electricity and magnetism, atomic physics, and plasma physics. The uncontrollability, the unreproducibility, and the sheer enormity of the phenomena will keep experimentalists and theorists busy but unsatisfied for many years to come. The greatest challenge in this field of <span class="hlt">research</span> is an adequate experimentally verifiable theory of the local energization of <span class="hlt">auroral</span> particle fluxes. Once that is achieved, there is every likelihood that the multitude of correlations between <span class="hlt">auroral</span> phenomena can be understood and appreciated. Until that time, however, such correlations are to be regarded like icebergs-the parts that can be seen are only a small fraction of the whole phenomenon, and it is the large unseen parts that can be dangerous to theorists and experimentalists alike. PMID:17842831</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850062287&hterms=radar+theory&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dradar%2Btheory','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850062287&hterms=radar+theory&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dradar%2Btheory"><span id="translatedtitle">Plasma irregularities associated with a morning discrete <span class="hlt">auroral</span> arc - Radar interferometer observations and theory</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Providakes, J.; Farley, D. T.; Swartz, W. E.; Riggin, D.</p> <p>1985-01-01</p> <p>A description is given of E region <span class="hlt">auroral</span> plasma irregularities associated with an intense <span class="hlt">auroral</span> morning arc observed over Fort Churchill by radar. The observations are compared with data from an all-sky camera (ASC) operated at Fort Churchill by the National <span class="hlt">Research</span> Council of Canada. The particular event described was chosen because of the rapid variation in structure and motion of the arc as it traveled through the radar beam. The horizontal vector electron drift velocity and electric field along the poleward boundary of the morning discrete <span class="hlt">auroral</span> arc was successfully measured with a radar interferometer. This instrument provided information concerning the temporal and spatial structure of the electrostatic plasma turbulence in the arc. The observations are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016E%26SS....3..257C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016E%26SS....3..257C&link_type=ABSTRACT"><span id="translatedtitle">A real-time hybrid aurora alert system: Combining citizen science reports with an <span class="hlt">auroral</span> oval model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Case, N. A.; Kingman, D.; MacDonald, E. A.</p> <p>2016-06-01</p> <p>Accurately predicting when, and from where, an aurora will be visible is particularly difficult, yet it is a service much desired by the general public. Several aurora alert services exist that attempt to provide such predictions but are, generally, based upon fairly coarse estimates of <span class="hlt">auroral</span> <span class="hlt">activity</span> (e.g., Kp or Dst). Additionally, these services are not able to account for a potential observer's local conditions (such as cloud cover or level of darkness). Aurorasaurus, however, combines data from the well-used, solar wind-driven, OVATION Prime <span class="hlt">auroral</span> oval model with real-time observational data provided by a global network of citizen scientists. This system is designed to provide more accurate and localized alerts for <span class="hlt">auroral</span> visibility than currently available. Early results are promising and show that over 100,000 <span class="hlt">auroral</span> visibility alerts have been issued, including nearly 200 highly localized alerts, to over 2000 users located right across the globe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1016154','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1016154"><span id="translatedtitle">Clean Coal Program <span class="hlt">Research</span> <span class="hlt">Activities</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Larry Baxter; Eric Eddings; Thomas Fletcher; Kerry Kelly; JoAnn Lighty; Ronald Pugmire; Adel Sarofim; Geoffrey Silcox; Phillip Smith; Jeremy Thornock; Jost Wendt; Kevin Whitty</p> <p>2009-03-31</p> <p>Although remarkable progress has been made in developing technologies for the clean and efficient utilization of coal, the biggest challenge in the utilization of coal is still the protection of the environment. Specifically, electric utilities face increasingly stringent restriction on the emissions of NO{sub x} and SO{sub x}, new mercury emission standards, and mounting pressure for the mitigation of CO{sub 2} emissions, an environmental challenge that is greater than any they have previously faced. The Utah Clean Coal Program addressed issues related to innovations for existing power plants including retrofit technologies for carbon capture and sequestration (CCS) or green field plants with CCS. The Program focused on the following areas: simulation, mercury control, oxycoal combustion, gasification, sequestration, chemical looping combustion, materials investigations and student <span class="hlt">research</span> experiences. The goal of this program was to begin to integrate the experimental and simulation <span class="hlt">activities</span> and to partner with NETL <span class="hlt">researchers</span> to integrate the Program's results with those at NETL, using simulation as the vehicle for integration and innovation. The investigators also committed to training students in coal utilization technology tuned to the environmental constraints that we face in the future; to this end the Program supported approximately 12 graduate students toward the completion of their graduate degree in addition to numerous undergraduate students. With the increased importance of coal for energy independence, training of graduate and undergraduate students in the development of new technologies is critical.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984AdSpR...4..491C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984AdSpR...4..491C"><span id="translatedtitle">Origin of <span class="hlt">auroral</span> electric potential structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chiu, Y. T.</p> <p></p> <p>Available observational data and theoretical models of the formation of <span class="hlt">auroral</span> electric potential structures are reviewed. It is shown that the principle of arc formation in the aurora can also be applied to other geomagnetic configurations, in order to construct a comprehensive theory of discrete <span class="hlt">auroral</span> arcs. According to the theory, the completion of the field-aligned current circuit in the aurora can lead to downward parallel electric fields in the return current from the central region of discrete arc potential. It is pointed out that evidence for downward parallel electric field signatures has been collected within the last year.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.6174R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.6174R"><span id="translatedtitle">Multi-spacecraft Observation of <span class="hlt">Auroral</span> Kilometric Radiation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Romantsova, T. V.; Mogilevsky, M. M.; Hanasz, J.; Skalsky, A. A.; Rusanov, A. A.</p> <p></p> <p>The <span class="hlt">Auroral</span> Kilometric Radiation observed typically at frequencies centered around 250kHz is generated in the night sector of the EarthSs magnetosphere and is closely linked with geomagnetic <span class="hlt">activities</span>. The present study takes an advantage of the si- multaneous wave observations onboard POLAR, GEOTAIL, INTERBALL-1 and -2 spacecraft which have different locations in the near-EarthSs space. Comparative anal- ysis of AKR observations made at different locations from the source region brings an important information on the AKR wave modes, source region characteristics and plasma properties along the way of emission propagation. Work supported by grant INTAS 99-1006 and RFBR 02-02-1753</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPSC...10..302G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPSC...10..302G"><span id="translatedtitle">Stratospheric benzene and hydrocarbon aerosols in Saturn's <span class="hlt">auroral</span> regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guerlet, S.; Fouchet, T.; Vinatier, S.; Simon, A. A.; Dartois, E.; Spiga, A.</p> <p>2015-10-01</p> <p>Saturn's polar upper atmosphere exhibits significant <span class="hlt">auroral</span> <span class="hlt">activity</span>, however, its impact on stratospheric chemistry (i.e.the production of benzene and heavier hydrocarbons) and thermal structure is poorly documented. Here we report on the first measurement of benzene column abundance in Saturn's polar stratosphere, together with the first detection of spectral sig- natures of the polar haze in the thermal infrared, based on limb measurements from the Composite Infrared Spectrometer (CIRS) on board Cassini. We then evaluate the radiative impact of the polar haze.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006EP%26S...58.1107I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006EP%26S...58.1107I"><span id="translatedtitle">Preliminary results of rocket attitude and <span class="hlt">auroral</span> green line emission rate in the DELTA campaign</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iwagami, Naomoto; Komada, Sayaka; Takahashi, Takao</p> <p>2006-09-01</p> <p>The attitude of a sounding rocket launched in the DELTA (Dynamics and Energetics of the Lower Thermosphere in Aurora) campaign was determined with IR horizon sensors and geomagnetic sensors. Since the payload was separated into two portions, two sets of attitude sensors were needed. A new IR sensor was developed for the present experiment, and found the zenith-angle of the spin-axis of the rocket with an accuracy of 2°. By combining information obtained by both type of sensors, the absolute attitudes were determined. The <span class="hlt">auroral</span> green line emission rate was measured by a photometer on board the same rocket launched under <span class="hlt">active</span> <span class="hlt">auroral</span> conditions, and the energy flux of the <span class="hlt">auroral</span> particle precipitation was estimated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5961841','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5961841"><span id="translatedtitle">Drifts of <span class="hlt">auroral</span> structures and magnetospheric electric fields</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nakamura, Rumi; Oguti, Takasi )</p> <p>1987-10-01</p> <p>Drifts of pulsating <span class="hlt">auroral</span> patches and discrete <span class="hlt">auroral</span> arc fragments are analyzed on the basis of all-sky TV observations of auroras. The drifts of <span class="hlt">auroral</span> structures in this study correspond on a gross scale with other measurements of magnetospheric convection. The result strongly suggests that not only <span class="hlt">auroral</span> patches but also arc fragments, when detached from the main body of the discrete aurora, drift owing to the magnetospheric electric fields. The measurement of the drifts of <span class="hlt">auroral</span> structures could possibly provide us with a convenient and accurate method to estimate the magnetospheric electric fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5340864','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5340864"><span id="translatedtitle">Integral probability of <span class="hlt">auroral</span> electron flux events from SSJ/4 DMSP F9 electron measurements. Interim report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hardy, D.A.; Bounar, K.H.</p> <p>1992-05-18</p> <p>A study has been completed to determine the probability of observing different levels of <span class="hlt">auroral</span> electron precipitation both within fixed spatial elements in magnetic local time and corrected geomagnetic latitude, and within spatial elements when the magnetic local time is fixed but the latitude range can be varied. The <span class="hlt">auroral</span> electron precipitation probability is defined for a series of thresholds in electron average energy and electron energy flux as a function of geomagnetic <span class="hlt">activity</span>. The study provides the capability to determine the probability of observation of an <span class="hlt">auroral</span> electron precipitation event for any specified threshold in average energy, energy flux, and level of geomagnetic <span class="hlt">activity</span> for any location in the <span class="hlt">auroral</span> region or for any line of sight through the <span class="hlt">auroral</span> region. The input for the study is one year of data from the SSJ/4 electron and proton spectrometer flown on the F9 satellite of the Defense Meteorological Satellite Program (DMSP) comprising approximately 10, 141 hemispheric passes through the <span class="hlt">auroral</span> region. The binning technique used to determine these probabilities is presented and some results are discussed. The operation of the software package to display the probability results is described. Defense Meteorological Satellite Program (DMSP), Aurora, Precipitating electrons, Geomagnetic Kp index, Integral probability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060029166&hterms=feather&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dfeather','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060029166&hterms=feather&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dfeather"><span id="translatedtitle">Matching software practitioner needs to <span class="hlt">researcher</span> <span class="hlt">activities</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feather, M. S.; Menzies, T.; Connelly, J. R.</p> <p>2003-01-01</p> <p>We present an approach to matching software practitioners' needs to software <span class="hlt">researchers</span>' <span class="hlt">activities</span>. It uses an accepted taxonomical software classfication scheme as intermediary, in terms of which practitioners express needs, and <span class="hlt">researchers</span> express <span class="hlt">activities</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSM43A1898B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSM43A1898B"><span id="translatedtitle"><span class="hlt">Auroral</span> Radio Emission Direction of Arrival Studies of Simultaneous Medium Frequency Burst and <span class="hlt">Auroral</span> Hiss</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Broughton, M.; Labelle, J. W.</p> <p>2010-12-01</p> <p>The <span class="hlt">auroral</span> zone is the source of multiple kinds of radio emissions that can be observed on the ground. The study of radio emissions offers a way to remotely sense space plasma processes and, in the case of <span class="hlt">auroral</span> emissions, to use the <span class="hlt">auroral</span> ionosphere as a large-scale plasma physics laboratory. Medium frequency (MF) burst is an impulsive radio emission at 1.5-4.5 MHz observed on the ground. Its generation mechanism is unknown, and it is often associated with the onset of substorms. <span class="hlt">Auroral</span> hiss is an impulsive emission observed on the ground at frequencies up to 1 MHz and is also associated with substorm onset. LaBelle et al. [1997] reported a temporal relationship between MF burst and <span class="hlt">auroral</span> hiss. Multiple impulses of both MF burst and <span class="hlt">auroral</span> hiss occurred simultaneously over a time period that in certain cases lasted tens of minutes. While the temporal relationship on the timescale of seconds is well established, the spatial relationship between MF burst and <span class="hlt">auroral</span> hiss has yet to be investigated. Dartmouth College currently operates a broadband (0-5 MHz) four-element radio interferometer at Toolik Field Station in Alaska (68° 38' N, 149° 36' W, 68.5° magnetic latitude) in order to study the direction of arrival (DOA) of radio emissions. Since the antenna spacing is 50 meters, the interferometer is optimized for DOA measurements of MF bursts. However, in certain cases, it can provide the DOA for the high-frequency portion of impulsive <span class="hlt">auroral</span> hiss. We present two case studies that represent the first simultaneous DOA measurements of impulsive <span class="hlt">auroral</span> hiss and MF burst. On March 4, 2010, the DOA of MF burst was predominantly from 30 degrees south of east, an observation consistent with the statistical work performed by Bunch et al. [2009]. Simultaneous DOA measurements of the high-frequency portion of <span class="hlt">auroral</span> hiss also showed the DOA as approximately 30 degrees south of east but with greater scatter in the data. The second case study, which involved an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/207164','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/207164"><span id="translatedtitle">A study of dayside <span class="hlt">auroral</span> bright spots seen by the Viking <span class="hlt">auroral</span> imager</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vo, H.B.; Murphree, J.S.</p> <p>1995-03-01</p> <p>The authors study Viking <span class="hlt">auroral</span> images in the UV Lyman, Birge, Hopfield wavelength range for correlation of dayside <span class="hlt">auroral</span> bright spots with various solar wind parameters. Such bright spots are seen primarily in the 1400 - 1600 MLT afternoon period, as one to four spots simultaneously, and commonly correlate with high solar wind speed, low solar wind density, radial interplanetary magnetic field. They show no correlation with solar wind pressure, B{sub z}, or B{sub x}.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890024146&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcalvert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890024146&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcalvert"><span id="translatedtitle">Mapping of <span class="hlt">auroral</span> kilometric radiation sources to the aurora</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Huff, R. L.; Calvert, W.; Craven, J. D.; Frank, L. A.; Gurnett, D. A.</p> <p>1988-01-01</p> <p><span class="hlt">Auroral</span> kilometric radiation (AKR) and optical <span class="hlt">auroral</span> emissions are observed simultaneously using plasma wave instrumentation and <span class="hlt">auroral</span> imaging photometers carried on the DE 1 spacecraft. The DE 1 plasma wave instrument measures the relative phase of signals from orthogonal electric dipole antennas, and from these measurements, apparent source directions can be determined with a high degree of precision. Wave data are analyzed for several strong AKR events, and source directions are determined for several emission frequencies. By assuming that the AKR originates at cyclotron resonant altitudes, a candidate source field line is identified. When the selected source field line is traced down to <span class="hlt">auroral</span> altitudes on the concurrent DE 1 <span class="hlt">auroral</span> image, a striking correspondece between the AKR source field line and localized <span class="hlt">auroral</span> features is produced. The magnetic mapping study provides strong evidence that AKR sources occur on field lines associated with discrete <span class="hlt">auroral</span> arcs, and it provides confirmation that AKR is generated near the electron cyclotron frequency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930049294&hterms=Auroras&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DAuroras','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930049294&hterms=Auroras&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DAuroras"><span id="translatedtitle">Equatorward and poleward expansion of the auroras during <span class="hlt">auroral</span> substorms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nakamura, Rumi; Oguti, Takasi; Yamamoto, Tatsundo; Kokubun, Susumu</p> <p>1993-01-01</p> <p>The formation of the <span class="hlt">auroral</span> bulge is investigated on the basis of all-sky TV <span class="hlt">auroral</span> data with high spatial and temporal resolution. Ways in which the discrete <span class="hlt">auroral</span> structures within the poleward expanding bulge develop systematically toward the west, the east, and also equatorward from a localized breakup region are shown. <span class="hlt">Auroral</span> structure at the western end of the bulge (a surge) develops with clockwise rotation as viewed along the magnetic field direction. At the eastern part of the bulge, thin <span class="hlt">auroral</span> features propagate eastward from the breakup region. Around the central meridian of the bulge, <span class="hlt">auroral</span> features expand equatorward and become north-south aligned (the N-S aurora). The N-S aurora and the eastward propagating aurora develop into diffuse and pulsating aurora after the expansion. It is suggested that these discrete <span class="hlt">auroral</span> structures in the bulge develop along the plasma streamlines in a localized distorted two-cell equipotential distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740018764','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740018764"><span id="translatedtitle">Rocket investigations of the <span class="hlt">auroral</span> electrojet</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Davis, T. N.</p> <p>1973-01-01</p> <p>Five Nike-Tomahawk rockets were flown to measure perturbations in the magnitude of the geomagnetic field due to <span class="hlt">auroral</span> electrojets. The dates and locations of the rocket launches are given along with a brief explanation of payloads and instrumentation. Papers published as a result of the project are listed. An abstract is included which outlines the scientific results from one of the flights.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870013894','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870013894"><span id="translatedtitle">Particle simulation of <span class="hlt">auroral</span> double layers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, Bruce L.; Okuda, Hideo</p> <p>1987-01-01</p> <p>Work on the simulation of <span class="hlt">auroral</span> double layers (DLs) with realistic particle-in-cell models is presented. An early model simulated weak DLs formed in a self-consistent circuit but under conditions subject to the ion-acoustic instability. Recent work has focused on strong DLs formed when currentless jets are injected into a dipole magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22224190','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22224190"><span id="translatedtitle">Numerical and laboratory simulations of <span class="hlt">auroral</span> acceleration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gunell, H.; De Keyser, J.; Mann, I.</p> <p>2013-10-15</p> <p>The existence of parallel electric fields is an essential ingredient of <span class="hlt">auroral</span> physics, leading to the acceleration of particles that give rise to the <span class="hlt">auroral</span> displays. An <span class="hlt">auroral</span> flux tube is modelled using electrostatic Vlasov simulations, and the results are compared to simulations of a proposed laboratory device that is meant for studies of the plasma physical processes that occur on <span class="hlt">auroral</span> field lines. The hot magnetospheric plasma is represented by a gas discharge plasma source in the laboratory device, and the cold plasma mimicking the ionospheric plasma is generated by a Q-machine source. In both systems, double layers form with plasma density gradients concentrated on their high potential sides. The systems differ regarding the properties of ion acoustic waves that are heavily damped in the magnetosphere, where the ion population is hot, but weakly damped in the laboratory, where the discharge ions are cold. Ion waves are excited by the ion beam that is created by acceleration in the double layer in both systems. The efficiency of this beam-plasma interaction depends on the acceleration voltage. For voltages where the interaction is less efficient, the laboratory experiment is more space-like.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26SS....3...15S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26SS....3...15S"><span id="translatedtitle">Geophysicochemical model of an ionospheric <span class="hlt">auroral</span> gyroscope</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Serban, Andreea I.; Geicu, Ovidiu I.; Serban, Florea</p> <p>2016-01-01</p> <p>This study presents a geophysicochemical model of an ionospheric <span class="hlt">auroral</span> gyroscope. The gyroscopic effect occurs due to the electromagnetic interaction in Earth's polar regions between two types of vertical cavity auroras: the herpolhodic cone (proton cavity aurora), operating in the cusp polar region, and two polhodic cones (an electronic cone and a protonic cone), operating in the aurora region. The ratio between the angular speeds of the herpolhodic and polhodic cones is established by the angle between Earth's rotational axis and the geomagnetic dipole axis. We have developed a theory of the ionospheric <span class="hlt">auroral</span> gyroscope as a kinematic part of the terrestrial magnetosphere and ionosphere that enables a unified explanation of important macroscopic phenomena that occur at this level. Accordingly, we have explained the oval shape of the polar auroras, Schumann resonances, geomagnetic micropulsation excitation, and the structuring of Earth's areas of radiation. The terrestrial gravitomagnetic field and dark matter are implicated in the initiation and behavior of the <span class="hlt">auroral</span> ionospheric gyroscope, both of which provide stability and accuracy. Viewed in a wider context, the ionospheric <span class="hlt">auroral</span> gyroscope theory could offer a way to experimentally investigate dark matter on Earth. Furthermore, it may have a potential value as a predictive tool, providing information about the large earthquakes and Earth's phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21280811','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21280811"><span id="translatedtitle"><span class="hlt">Auroral</span> imaging from a spinning satellite.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mende, Stephen B</p> <p>2011-01-01</p> <p>For optimizing in situ particle and field measurements, <span class="hlt">auroral</span> <span class="hlt">research</span> satellites are best operated in a spinning mode. Simultaneous imaging of the optical aurora from such satellites requires either a stable platform or the derotation of the camera itself. Either of these requirements is complex and expensive. Either of these solutions also suffers from the problem that image blur often occurs due to the misalignments between the actual and the nominal spin axes of the satellite. Here we propose a novel solution in which the camera(s) are mounted solidly on the spacecraft to observe parallel to the spin axis of the satellite while a despinning flat 45° mirror directs the field of view toward the spacecraft nadir. The resultant image will appear to rotate in the frame of reference of the detector in the camera. In our scheme the images are exposed rapidly and a derotation algorithm is applied to the coordinates of each pixel in real time before the images are co-added in memory. The derotation algorithm uses only look up tables and integer additions and can be executed rapidly in hardware so that the system can support relatively fast satellite spin cycles. The system was simulated including a 1.8° misalignment between the nominal satellite spin axis (parallel to the mirror rotation axis) and the actual spin axis. It was shown that the look up table based algorithm can despin the images and correct for the axes misalignment, allowing the observation of the aurora at full resolution and with continuous coverage. PMID:21280811</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015A%26A...580A..89G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015A%26A...580A..89G"><span id="translatedtitle">Stratospheric benzene and hydrocarbon aerosols detected in Saturn's <span class="hlt">auroral</span> regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guerlet, S.; Fouchet, T.; Vinatier, S.; Simon, A. A.; Dartois, E.; Spiga, A.</p> <p>2015-08-01</p> <p>Context. Saturn's polar upper atmosphere exhibits significant <span class="hlt">auroral</span> <span class="hlt">activity</span>; however, its impact on stratospheric chemistry (i.e. the production of benzene and heavier hydrocarbons) and thermal structure remains poorly documented. Aims: We aim to bring new constraints on the benzene distribution in Saturn's stratosphere, to characterize polar aerosols (their vertical distribution, composition, thermal infrared optical properties), and to quantify the aerosols' radiative impact on the thermal structure. Methods: Infrared spectra acquired by the Composite Infrared Spectrometer (CIRS) on board Cassini in limb viewing geometry are analysed to derive benzene column abundances and aerosol opacity profiles over the 3 to 0.1 mbar pressure range. The spectral dependency of the haze opacity is assessed in the ranges 680-900 and 1360-1440 cm-1. Then, a radiative climate model is used to compute equilibrium temperature profiles, with and without haze, given the haze properties derived from CIRS measurements. Results: On Saturn's <span class="hlt">auroral</span> region (80°S), benzene is found to be slightly enhanced compared to its equatorial and mid-latitude values. This contrasts with the Moses & Greathouse (2005, J. Geophys. Res., 110, 9007) photochemical model, which predicts a benzene abundance 50 times lower at 80°S than at the equator. This advocates for the inclusion of ion-related reactions in Saturn's chemical models. The polar stratosphere is also enriched in aerosols, with spectral signatures consistent with vibration modes assigned to aromatic and aliphatic hydrocarbons, and presenting similarities with the signatures observed in Titan's stratosphere. The aerosol mass loading at 80°S is estimated to be 1-4 × 10-5 g cm-2, an order of magnitude less than on Jupiter, which is consistent with the order of magnitude weaker <span class="hlt">auroral</span> power at Saturn. We estimate that this polar haze warms the middle stratosphere by 6 K in summer and cools the upper stratosphere by 5 K in winter. Hence</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMSM23A2536H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMSM23A2536H&link_type=ABSTRACT"><span id="translatedtitle">Evolution of <span class="hlt">auroral</span> acceleration region field-aligned current systems, plasma, and potentials observed by Cluster during substorms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hull, A. J.; Chaston, C. C.; Fillingim, M. O.; Frey, H. U.; Goldstein, M. L.; Bonnell, J. W.; Mozer, F.</p> <p>2015-12-01</p> <p>The <span class="hlt">auroral</span> acceleration region is an integral link in the chain of events that transpire during substorms, and the currents, plasma and electric fields undergo significant changes driven by complex dynamical processes deep in the magnetotail. The acceleration processes that occur therein accelerate and heat the plasma that ultimately leads to some of the most intense global substorm <span class="hlt">auroral</span> displays. Though this region has garnered considerable attention, the temporal evolution of field-aligned current systems, associated acceleration processes, and resultant changes in the plasma constituents that occur during key stages of substorm development remain unclear. In this study we present a survey of Cluster traversals within and just above the <span class="hlt">auroral</span> acceleration region (≤3 Re altitude) during substorms. Particular emphasis is on the spatial morphology and developmental sequence of <span class="hlt">auroral</span> acceleration current systems, potentials and plasma constituents, with the aim of identifying controlling factors, and assessing <span class="hlt">auroral</span> emmission consequences. Exploiting multi-point measurements from Cluster in combination with <span class="hlt">auroral</span> imaging, we reveal the injection powered, Alfvenic nature of both the substorm onset and expansion of <span class="hlt">auroral</span> particle acceleration. We show evidence that indicates substorm onsets are characterized by the gross-intensification and filamentation/striation of pre-existing large-scale current systems to smaller/dispersive scale Alfven waves. Such an evolutionary sequence has been suggested in theoretical models or single spacecraft data, but has not been demonstrated or characterized in multispacecraft observations until now. It is also shown how the Alfvenic variations over time may dissipate to form large-scale inverted-V structures characteristic of the quasi-static aurora. These findings suggest that, in addition to playing <span class="hlt">active</span> roles in driving substorm aurora, inverted-V and Alfvenic acceleration processes are causally linked. Key</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSA13B3991H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSA13B3991H"><span id="translatedtitle">Multi-Camera Reconstruction of Fine Scale High Speed <span class="hlt">Auroral</span> Dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirsch, M.; Semeter, J. L.; Zettergren, M. D.; Dahlgren, H.; Goenka, C.; Akbari, H.</p> <p>2014-12-01</p> <p>The fine spatial structure of dispersive aurora is known to have ground-observable scales of less than 100 meters. The lifetime of prompt emissions is much less than 1 millisecond, and high-speed cameras have observed <span class="hlt">auroral</span> forms with millisecond scale morphology. Satellite observations have corroborated these spatial and temporal findings. Satellite observation platforms give a very valuable yet passing glance at the <span class="hlt">auroral</span> region and the precipitation driving the aurora. To gain further insight into the fine structure of accelerated particles driven into the ionosphere, ground-based optical instruments staring at the same region of sky can capture the evolution of processes evolving on time scales from milliseconds to many hours, with continuous sample rates of 100Hz or more. Legacy <span class="hlt">auroral</span> tomography systems have used baselines of hundreds of kilometers, capturing a "side view" of the field-aligned <span class="hlt">auroral</span> structure. We show that short baseline (less than 10 km), high speed optical observations fill a measurement gap between legacy long baseline optical observations and incoherent scatter radar. The ill-conditioned inverse problem typical of <span class="hlt">auroral</span> tomography, accentuated by short baseline optical ground stations is tackled with contemporary data inversion algorithms. We leverage the disruptive electron multiplying charge coupled device (EMCCD) imaging technology and solve the inverse problem via eigenfunctions obtained from a first-principles 1-D electron penetration ionospheric model. We present the latest analysis of observed <span class="hlt">auroral</span> events from the Poker Flat <span class="hlt">Research</span> Range near Fairbanks, Alaska. We discuss the system-level design and performance verification measures needed to ensure consistent performance for nightly multi-terabyte data acquisition synchronized between stations to better than 1 millisecond.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060028679&hterms=feather&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dfeather','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060028679&hterms=feather&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dfeather"><span id="translatedtitle">Relating practitioner needs to <span class="hlt">research</span> <span class="hlt">activities</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feather, M. S.; Menzies, T.; Connelly, J. R.</p> <p>2003-01-01</p> <p>We present an approach to matching needs (practioner requirements) to solutions (<span class="hlt">researcher</span> <span class="hlt">activities</span>). A taxonomical classification scheme acts as intermediary between needs and <span class="hlt">activities</span>. Expert practitioners exprss their needs in terms of this taxonomy. <span class="hlt">Researchers</span> express their <span class="hlt">activities</span> in the same terms. A decision support tool is used to assist in the combination and study of their expressions of needs and <span class="hlt">activities</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM23A2209B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM23A2209B"><span id="translatedtitle">In situ observations of medium frequency <span class="hlt">auroral</span> radio emissions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Broughton, M.; Labelle, J. W.; Pfaff, R. F.; Parrot, M.; Yan, X.; Burchill, J. K.</p> <p>2013-12-01</p> <p>The <span class="hlt">auroral</span> ionosphere is a region rich with plasma waves that can be studied both in space and on the ground. These waves may mediate energy exchange between particle populations and provide information about the local plasma properties and boundaries. <span class="hlt">Auroral</span> medium frequency (MF) burst is an impulsive radio emission observed at ground-level from 1.3-4.5 MHz that is associated with local substorm onset. There have been two recent reports of impulsive, broadband, MF waves at high latitudes. Burchill and Pfaff [2005] reported observations from the FAST satellite of impulsive, broadband, MF and low frequency (LF) radio waves. Using data from the DEMETER satellite, Parrot et al. [2009] surveyed MF waves caused by lightning. This study did show a high-latitude population of MF waves. We investigate whether the waves observed by these two satellites are related to <span class="hlt">auroral</span> MF burst. Using FAST satellite burst mode electric field data from high-latitude (> 60 degrees magnetic), low-altitude (< 1000 km) intervals of moderate to large geomagnetic <span class="hlt">activity</span> (Kp > 3) from 1996-2002, we have found forty-four examples of impulsive MF waves, all of which are associated with impulsive LF waves. Although MF burst and the waves observed by FAST have similar spectral signatures, they have different magnetic local time dependencies, which suggests that they may be unrelated. A study of MF waves observed at high latitude by DEMETER is ongoing. In situ observations of MF burst could provide crucial information about this heretofore unexplained natural radio emission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AnGeo..32..623X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AnGeo..32..623X"><span id="translatedtitle">An empirical model of the <span class="hlt">auroral</span> oval derived from CHAMP field-aligned current signatures - Part 2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xiong, C.; Lühr, H.</p> <p>2014-06-01</p> <p>In this paper we introduce a new model for the location of the <span class="hlt">auroral</span> oval. The <span class="hlt">auroral</span> boundaries are derived from small- and medium-scale field-aligned current (FAC) based on the high-resolution CHAMP (CHAllenging Minisatellite Payload) magnetic field observations during the years 2000-2010. The basic shape of the <span class="hlt">auroral</span> oval is controlled by the dayside merging electric field, Em, and can be fitted well by ellipses at all levels of <span class="hlt">activity</span>. All five ellipse parameters show a dependence on Em which can be described by quadratic functions. Optimal delay times for the merging electric field at the bow shock are 30 and 15 min for the equatorward and poleward boundaries, respectively. A comparison between our model and the British Antarctic Survey (BAS) <span class="hlt">auroral</span> model derived from IMAGE (Imager for Magnetopause-to-Aurora Global Exploration) optical observations has been performed. There is good agreement between the two models regarding both boundaries, and the differences show a Gaussian distribution with a width of ±2° in latitude. The difference of the equatorward boundary shows a local-time dependence, which is 1° in latitude poleward in the morning sector and 1° equatorward in the afternoon sector of the BAS model. We think the difference between the two models is caused by the appearance of <span class="hlt">auroral</span> forms in connection with upward FACs. All information required for applying our <span class="hlt">auroral</span> oval model (CH-Aurora-2014) is provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED564829.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED564829.pdf"><span id="translatedtitle">OCLC <span class="hlt">Research</span>: 2012 <span class="hlt">Activity</span> Report</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>OCLC Online Computer Library Center, Inc., 2013</p> <p>2013-01-01</p> <p>The mission of the Online Computer Library Center (OCLC) <span class="hlt">Research</span> is to expand knowledge that advances OCLC's public purposes of furthering access to the world's information and reducing library costs. OCLC <span class="hlt">Research</span> is dedicated to three roles: (1)To act as a community resource for shared <span class="hlt">research</span> and development (R&D); (2) To provide advanced…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMSA23A1125L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMSA23A1125L"><span id="translatedtitle">Synoptical <span class="hlt">Auroral</span> Ovals: A Comparison study with TIMED/GUVI Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liou, K.; Paxton, L.; Zhang, Y.</p> <p>2007-12-01</p> <p>Whether the aurora Australis is a mirror image of its northern hemispheric counterpart is a question that <span class="hlt">auroral</span> physicists have been wanting to answer. Owing to geophysical constraints, especially the large offset between the location of the southern magnetic and southern geographic poles, there is a paucity of information about the aurora Australis. Comparisons of some instantansous global-scale northern and southern auroras acquired conjugately by Polar and IMAGE spacecraft recently have shown mixed results. In this study, we present data from a different source to provide insight into the global morphology and behavior of the <span class="hlt">auroral</span> oval. Approximately 20,000 Earth's disk FUV images acquired from the Global Ultraviolet Imager (GUVI) on-board NASA's Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) satellite between February 2002 and February 2006 are processed and analyzed. Synoptic <span class="hlt">auroral</span> distributions for the northern and southern ovals are derived. Our study result reveals that the statistical oval is nearly hemispherically symmetric (within ±80%). Several known features in the morphology of the aurora Borealis are also observed in the Southern Hemisphere: For instance, the <span class="hlt">auroral</span> midday gap and the premidnight maximum. The hemispherical symmetry of the auroras deteriorates as the partition of solar illumination in the two hemisphere polar region becomes asymmetric. It is estimated that the solar illumination effect accounts for up to ~50% of the hemispheric asymmetry. We found evidence that suggests that the aurora is suppressed under sunlit conditions in the South just as it is in the North. We also found that the <span class="hlt">auroral</span> energy flux increases monotonically with the increase of the solar zenith angle. These results suggest that ionospheric conductivity plays an <span class="hlt">active</span> role in regulating magnetospheric energy deposition in the <span class="hlt">auroral</span> zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E1941T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E1941T&link_type=ABSTRACT"><span id="translatedtitle">PC Index as a Means to Monitor Processes in the <span class="hlt">Auroral</span> Zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Troshichev, Oleg</p> <p>2016-07-01</p> <p>The PC index was introduced [Troshichev et al., 1988] to characterize the polar cap magnetic <span class="hlt">activity</span> generated by the geoeffective interplanetary electric field. Results of recent studies [Troshichev and Janzhura, 2012; Troshichev and Sormakov, 2015] are strongly indicative of PC index as a proxy of the solar wind energy that entered into the magnetosphere. The PC index in this charge can be successfully used to monitor processes in the <span class="hlt">auroral</span> zone: 1. PC index well correlates with intensity of the Region 1 field-aligned currents measured by SWARM satellites on the <span class="hlt">auroral</span> oval poleward boundary. As it is known, the R1 field-aligned currents flow into ionosphere in the morning <span class="hlt">auroral</span> oval and flow out of ionosphere in the evening oval. The R1 FAC intensity and, correspondingly, the PC value increase in tandem before the substorm sudden onset. 2. PC-index can be taken as Input Parameter in Empirical <span class="hlt">Auroral</span> Precipitation Model "OVATION-prime" [Newell, 2009] instead of the coupling function dØMP/dt. Use of the 1-min PC index in the modified OVATION-PC model provides the much better timing of the <span class="hlt">auroral</span> precipitation with allowance for actual state of the magnetosphere. 3. There is a strong correspondence between the behavior of PC and development of magnetic disturbances in the <span class="hlt">auroral</span> zone: the magnetic substorms are preceded by the PC index growth, the substorm onsets are commonly associated with a sharp increase in the PC growth rate, the substorm occurrence reaches the maximum when PC exceeds the threshold value ~ 1.5±0.5 mV/m, the linear correlation between the PC and AL values is typical of all classes of substorms, irrespective of their power. There regularities provide possibility to nowcast the substorm development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6688206','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6688206"><span id="translatedtitle"><span class="hlt">Auroral</span> ultraviolet darkening on the outer planets</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pryor, W.R.</p> <p>1989-01-01</p> <p>The Voyager 2 Photopolarimeter Subsystem (PPS) has made photometric observations of Jupiter at 2400 A and photometric and polarimetric observations of Saturn and Uranus at 2650 A. At these wavelengths the instrument is observing each planet's stratosphere and upper troposphere. The most striking features are that both poles of Jupiter and the observed northern pole of Saturn are very dark, while Uranus has a uniformly bright appearance. All three planets show evidence for a stratospheric haze. Simple vertically homogeneous multiple scattering models are used to characterize these stratospheric hazes. <span class="hlt">Aurores</span> occur at high latitudes on Jupiter and Saturn and at low latitudes on Uranus. The asymmetric polar darkening on Jupiter seen by PPS is roughly matched by the asymmetry in the <span class="hlt">auroral</span> zones. Historical data suggest that the haze asymmetry is persistent. The dark north polar cap seen by PPS at Saturn is small and close to the pole, which corresponds to the small <span class="hlt">auroral</span> zone close to the pole. A model is examined which attributes the darkening to <span class="hlt">auroral</span> bombardment initiating methane chemistry that makes dark hydrocarbon particles. Possible chemical pathways are discussed, and mass balance calculations are presented for Jupiter, Saturn, and Uranus. The model is quantitatively plausible for Jupiter and Saturn. The lack of localized darkening on Uranus can be explained in this model by noting that weak vertical mixing and methane condensation near the 1-bar level lead to negligible methane abundances at <span class="hlt">auroral</span> altitudes. The auroras must reach the methane for dark material to form. The thin haze that is seen on Uranus is ascribed to photochemical processes. Voyager 2 will reach Neptune this year. Ground-based observers have reported vigorous vertical mixing and large amounts of stratospheric methane there.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E2397A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E2397A"><span id="translatedtitle"><span class="hlt">Auroral</span> particle instrument onboard the INDEX satellite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Asamura, K.; Tsujita, D.; Tanaka, H.; Saito, Y.; Mukai, T.; Hirahara, M.</p> <p></p> <p>The INDEX satellite is a microsatellite which will be inserted into a low-altitude (650-800km) polar orbit by an H2A rocket as a piggyback payload. A low-energy plasma particle instrument, which consists of two sensor heads (ion/electrons sensors; ISA/ESA), and a multi-spectral <span class="hlt">auroral</span> camera (MAC) will be installed in the INDEX in order to investigate formation mechanisms of fine-scale structures of optical <span class="hlt">auroral</span> arc emissions. Because of the low-altitude orbit, the satellite velocity is relatively fast (7.5km/s). A high time-resolution, therefore, is necessary for the plasma measurement. The time resolution of the plasma instruments onboard the INDEX is 20ms, which corresponds to a spatial scale of 150m. The sensor heads are top-hat type analyzers with a planar field-of-view (FOV) which can cover basically 360 degrees in the azimuthal direction in case of no obstacles. Therefore, during the measurements, the attitude of the satellite will be controlled to include a geomagnetic field line within the planar FOV of the plasma instruments. At the same time with the <span class="hlt">auroral</span> particle observations, the FOV of the optical <span class="hlt">auroral</span> camera will be pointed to a footprint of the corresponding geomagnetic field line. In this case, pitch-angle distributions of <span class="hlt">auroral</span> particles can be obtained with the time resolution determined only by a period of internal energy scan, namely, 20ms. Since the instrument is designed to perform the measurement of high-time resolution, the instrument should be able to handle the high count rate. For this purpose, we apply an MCP detector with a position sensitive anode on the basis of a measurement of signal transmission time on the anode pattern. With this detector system, the instrument can handle 106 -107 counts per second.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMGC33A1250P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMGC33A1250P&link_type=ABSTRACT"><span id="translatedtitle">Crowd-sourcing, Communicating, and Improving <span class="hlt">Auroral</span> Science at the Speed of Social Media through Aurorasaurus.org</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Patel, K.; MacDonald, E.; Case, N.; Hall, M.; Clayton, J.; Heavner, M.; Tapia, A.; Lalone, N.; McCloat, S.</p> <p>2015-12-01</p> <p>On March 17, 2015, a geomagnetic storm—the largest of the solar cycle to date— hit Earth and gave many sky watchers around the world a beautiful <span class="hlt">auroral</span> display. People made thousands of aurora-related tweets and direct reports to Aurorasaurus.org, an interdisciplinary citizen science project that tracks auroras worldwide in real-time through social media and the project's apps and website. Through Aurorasaurus, <span class="hlt">researchers</span> are converting these crowdsourced observations into valuable data points to help improve models of where aurora can be seen. In this presentation, we will highlight how the team communicates with the public during these global, sporadic events to help drive and retain participation for Aurorasaurus. We will highlight some of the co-produced scientific results and increased media interest following this event. Aurorasaurus uses mobile apps, blogging, and a volunteer scientist network to reach out to aurora enthusiasts to engage in the project. Real-time tweets are voted on by other users to verify their accuracy and are pinned on a map located on aurorasaurus.org to help show the instantaneous, global <span class="hlt">auroral</span> visibility. Since the project launched in October 2014, hundreds of users have documented the two largest geomagnetic storms of this solar cycle. In some cases, like for the St. Patrick's Day storm, users even reported seeing aurora in areas different than aurora models suggested. Online analytics indicate these events drive users to our page and many also share images with various interest groups on social media. While citizen scientists provide observations, Aurorasaurus gives back by providing tools to help the public see and understand the aurora. When people verify <span class="hlt">auroral</span> sightings in a specific area, the project sends out alerts to nearby users of possible <span class="hlt">auroral</span> visibility. Aurorasaurus team members around the world also help the public understand the intricacies of space weather and aurora science through blog articles</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1792S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1792S"><span id="translatedtitle">Ground and satellite observations of <span class="hlt">auroral</span> fragmentation into patches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shiokawa, Kazuo; Nishi, Katsuki</p> <p>2016-07-01</p> <p>We review characteristic <span class="hlt">auroral</span> fragmentation which is the process by which uniform aurora is broken into several fragments to form <span class="hlt">auroral</span> patches, based on the all-sky camera observations at Tromsoe, Norway and THEMIS chain in Canada. The <span class="hlt">auroral</span> fragmentation occurs as finger-like structures developing predominantly in meridional direction with speeds of several tens m/s and scale sizes of several tens kilometers without any shearing motion. These features suggest that pressure-driven instability in the balance between the earthward magnetic-tension force and the tailward pressure gradient force in the magnetosphere is the main driving force of the <span class="hlt">auroral</span> fragmentation. Thus, these observations indicate that <span class="hlt">auroral</span> fragmentation associated with pressure-driven instability is a process that creates <span class="hlt">auroral</span> patches. <span class="hlt">Auroral</span> fragmentation is seen from midnight to dawn local time and usually appears at the beginning of the substorm recovery phase, near the low latitude boundary of the <span class="hlt">auroral</span> region. One example of plasma and magnetic field observations by the THEMIS satellite in the conjugate magnetosphere shows diamagnetic anti-phase variations of magnetic and plasma pressures with time scales of several to tens minutes associated with the <span class="hlt">auroral</span> fragmentation. This observation also supports the idea of pressure-driven instability to cause the <span class="hlt">auroral</span> fragmentation into patches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=test+AND+motivation+AND+Spanish&pg=4&id=EJ738926','ERIC'); return false;" href="http://eric.ed.gov/?q=test+AND+motivation+AND+Spanish&pg=4&id=EJ738926"><span id="translatedtitle"><span class="hlt">Active</span> Learning in Aging <span class="hlt">Research</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Singelis, Theodore M.</p> <p>2006-01-01</p> <p>This article describes the involvement of undergraduate students in <span class="hlt">research</span> at the California State University (CSU), Chico funded through an Academic <span class="hlt">Research</span> Enhancement Award (AREA) from the National Institute on Aging (NIA). CSU, Chico is a "teaching" university and has students with a variety of motivations and abilities. The 3-year research…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=lopatin&id=EJ470921','ERIC'); return false;" href="http://eric.ed.gov/?q=lopatin&id=EJ470921"><span id="translatedtitle">Supporting Student <span class="hlt">Research</span> Group <span class="hlt">Activities</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Lopatin, Dennis E.</p> <p>1993-01-01</p> <p>This discussion describes methods that foster a healthy Student <span class="hlt">Research</span> Group (SRG) and permits it to fulfill its responsibility in the development of the student <span class="hlt">researcher</span>. The model used in the discussion is that of the University of Michigan School of Dentistry SRG. (GLR)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFMSA51A4067K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFMSA51A4067K&link_type=ABSTRACT"><span id="translatedtitle">Comparing <span class="hlt">Auroral</span> Far Ultraviolet Images and Coincident Ionosonde Observations of the <span class="hlt">Auroral</span> E Region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Knight, H. K., Jr.; Galkin, I. A.; Reinisch, B. W.</p> <p>2014-12-01</p> <p>Comparisons are being made between <span class="hlt">auroral</span> ionospheric E region parameters derived from two types of observations: satellite-based far ultraviolet (FUV) imagers and ground-based ionosondes. The FUV imagers are: 1) NASA's Thermosphere Ionosphere Mesosphere Energetics and Dynamics Global Ultraviolet Imager (TIMED/GUVI) and 2) DMSP's Special Sensor Ultraviolet Spectrographic Imager (SSUSI). The ionosondes are five high latitude Digisondes included in the Global Ionospheric Radio Observatory (GIRO) (Reinisch and Galkin, EPS, 2011). The purpose of the comparisons is to determine whether <span class="hlt">auroral</span> FUV remote sensing algorithms that derive E region parameters from Lyman-Birge-Hopfield (LBH) emissions are biased in the presence of proton aurora. Earlier comparisons between FUV images and in situ <span class="hlt">auroral</span> particle flux observations (e.g., Knight et al., JGR, 2012) indicate that proton aurora is much more efficient than electron aurora in producing LBH emission, and to be consistent with these findings the FUV-ionosonde comparisons would have to show that <span class="hlt">auroral</span> FUV-derived NmE (maximum E region electron density) is biased high in the presence of proton precipitation. The advantage of making comparisons with Digisonde observations of the E region (as opposed to incoherent scatter radar) is that Digisondes remain in operation continuously over extended periods of time (i.e. years) and record observations every few minutes, making it possible to gather large numbers of FUV image-coincident observations for statistical studies. The subject of how to interpret <span class="hlt">auroral</span> E region traces in ionograms has not been studied much up to now, however, and we are making progress in that area. We have found that a modified version of the rules from Piggott and Rawer, U.R.S.I. Handbook of Ionogram Interpretation and Reduction(1972) gives a large number of usable ionograms and good correlation with <span class="hlt">auroral</span> FUV observations. The figure shows an example of an <span class="hlt">auroral</span> FUV image with the locations</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006GeoRL..3312106M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006GeoRL..3312106M"><span id="translatedtitle">Observations of amplitude saturation in ELF/VLF wave generation by modulated HF heating of the <span class="hlt">auroral</span> electrojet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moore, R. C.; Inan, U. S.; Bell, T. F.</p> <p>2006-06-01</p> <p>We present detailed observations of the onset of amplitude saturation in ELF/VLF waves generated via modulated HF heating of naturally-forming, large-scale current systems, such as the <span class="hlt">auroral</span> electrojet. Broadband ELF/VLF measurements at a ground-based receiver located near the High-Frequency <span class="hlt">Active</span> <span class="hlt">Auroral</span> <span class="hlt">Research</span> Program (HAARP) HF transmitter in Gakona, Alaska, exhibit variations in signal amplitude which are qualitatively consistent with a hard-limiting approximation of the saturation process. A method to approximate the saturation curve as a function of HF power from experimental data is presented, and the results indicate that a ~5-10% reduction in generated ELF signal amplitude is typical at the maximum radiated HF power level (771 kW) for modulation frequencies between 1225 Hz and 3365 Hz. For HF transmissions using sinusoidal amplitude modulation, the saturation dominantly affects the second harmonic of the generated ELF/VLF signal, with amplitudes on average 16% lower than expected at the maximum HF power level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA21B2125S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA21B2125S"><span id="translatedtitle">Comparison between triangulated <span class="hlt">auroral</span> altitude and precipitating electron energy flux</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sangalli, L.; Partamies, N. J.; Gustavsson, B.</p> <p>2012-12-01</p> <p>The MIRACLE network monitors <span class="hlt">auroral</span> <span class="hlt">activity</span> in the Fennoscandian sector of Europe. Network stations cover the range of 55° to 57° magnetic latitude North and span two hours in magnetic local time. Some of the MIRACLE network stations include digital all-sky cameras (ASC) with overlapping field-of-views at the latitude aurora occurs. The ASCs in this network operate at three different wavelengths: 427.8 nm (blue line), 557.7 nm (green line) and 630.0 nm (red line). These wavelengths are selected using narrow band filters. Red and blue lines images are recorded once per minute and green line images every 20 s. On January 31, 2001 multiple discrete arcs were observed at the zenith of the ASC located in Muonio (67.9° N, 23.6° E) and were visible in other stations. The peak <span class="hlt">auroral</span> emission is estimated using triangulation between pairs of stations and compared with precipitating electron energy fluxes inverted from ASC images and measured in situ on the DMSP satellite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSA51A2051S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSA51A2051S"><span id="translatedtitle">Comparison between triangulated <span class="hlt">auroral</span> altitude and precipitating electron energy flux</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sangalli, L.; Partamies, N. J.; Gustavsson, B.</p> <p>2013-12-01</p> <p>The MIRACLE network monitors <span class="hlt">auroral</span> <span class="hlt">activity</span> in the Fennoscandian sector of Europe. Network stations cover the range of 55° to 57° magnetic latitude North and span two hours in magnetic local time. Some of the MIRACLE network stations include digital all-sky cameras (ASC) with overlapping field-of-views at the latitude aurora occurs. The ASCs in this network operate at three different wavelengths: 427.8 nm (blue line), 557.7 nm (green line) and 630.0 nm (red line). These wavelengths are selected using narrow band filters. Red and blue lines images are recorded once per minute and green line images every 20 s. On January 31, 2001 multiple discrete arcs were observed at the zenith of the ASC located in Muonio (67.9° N, 23.6° E) and were visible in other stations. The peak <span class="hlt">auroral</span> emission is estimated using triangulation between pairs of stations and compared with precipitating electron energy fluxes inverted from ASC images and measured in situ on the DMSP satellite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFMSM13B2368G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012AGUFMSM13B2368G&link_type=ABSTRACT"><span id="translatedtitle">Untangling the Space-Time Ambiguity of <span class="hlt">Auroral</span> Emissions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gjerloev, J. W.; Humberset, B.; Michell, R. G.; Samara, M.; Mann, I. R.</p> <p>2012-12-01</p> <p>In this paper we address the spatiotemporal characteristics of the magnetosphere-ionosphere (M-I) system as observed by an all-sky imager (ASI). We utilize 557.7 nm images obtained by a ground based ASI located under the dark ionosphere (~22 MLT) at Poker Flat, Alaska. The 19 min movie was recorded at 3.31 Hz during continuous moderately intense <span class="hlt">auroral</span> <span class="hlt">activity</span> driven by a southward IMF Bz of about -5 nT. We analyze this movie using a simple, yet robust, 2D FFT technique that allows us to determine the scale size dependent variability. When plotting the correlation pattern as a function of scale size and time separation we find a pattern with distinct regions of high and low correlation. Larger scale sizes are found to have longer duration. We interpret this remarkable result as indicative of a M-I system that uses repeatable solutions to transfer energy and momentum from the magnetosphere to the ionosphere. Our findings support the characteristics of the field-aligned currents as determined from multi-point satellite observations (ST-5, Gjerloev et al., Annales Geophysicae, 2011). Two different electromagnetic parameters, <span class="hlt">auroral</span> emissions and field-aligned currents, display similar characteristics supporting our conclusion that this is indicative of a fundamental behavior of the M-I system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880042160&hterms=southwest+iowa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsouthwest%2Biowa','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880042160&hterms=southwest+iowa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsouthwest%2Biowa"><span id="translatedtitle">Electron density depletions in the nightside <span class="hlt">auroral</span> zone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Persoon, A. M.; Gurnett, D. A.; Peterson, W. K.; Waite, J. H., Jr.; Burch, J. L.; Green, J. L.</p> <p>1988-01-01</p> <p>Dynamics Explorer 1 measurements are used to investigate regions of low electron density in the nightside <span class="hlt">auroral</span> zone. Sharply defined regions of low electron density are found in <span class="hlt">auroral</span> zone crossings from the predusk hours until the early morning hours at all radial distances up to at least 4.6 earth radii. Densities in the <span class="hlt">auroral</span> cavity are shown to fall to values below 0.3/cu cm. Within the <span class="hlt">auroral</span> cavity, electron-density-profile variations of a factor of 2 or more on spatial scales of tens of kilometers are found, and the electron plasma frequency to electron cyclotron frequency ratios are 0.02-0.4. The results suggest associations between the density depletions in the nightside <span class="hlt">auroral</span> zone and <span class="hlt">auroral</span> acceleration processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730015682','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730015682"><span id="translatedtitle">Analysis of data of the 1968-1969 airborne <span class="hlt">auroral</span> expeditions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mende, S. B.</p> <p>1973-01-01</p> <p>Data collected by the CV-990 aircraft on two <span class="hlt">auroral</span> expeditions are reported. Two problems, (1) coordinated <span class="hlt">auroral</span> particle and optical observations, and (2) substorm effects in <span class="hlt">auroral</span> spectra, were studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850036995&hterms=electrodynamics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Delectrodynamics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850036995&hterms=electrodynamics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Delectrodynamics"><span id="translatedtitle">A numerical simulation of <span class="hlt">auroral</span> ionospheric electrodynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mallinckrodt, A. J.</p> <p>1985-01-01</p> <p>A computer simulation of <span class="hlt">auroral</span> ionospheric electrodynamics in the altitude range 80 to 250 km has been developed. The routine will either simulate typical electron precipitation profiles or accept observed data. Using a model background ionosphere, ion production rates are calculated from which equilibrium electron densities and the Hall and Pedersen conductivities may be determined. With the specification of suitable boundary conditions, the entire three-dimensional current system and electric field may be calculated within the simulation region. The results of the application of the routine to a typical inverted-V precipitation profile are demonstrated. The routine is used to explore the observed anticorrelation between electric field magnitude and peak energy in the precipitating electron spectrum of an <span class="hlt">auroral</span> arc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870045492&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcalvert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870045492&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcalvert"><span id="translatedtitle">The minimum bandwidths of <span class="hlt">auroral</span> kilometric radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baumback, M. M.; Calvert, W.</p> <p>1987-01-01</p> <p>The bandwidths of the discrete spectral components of the <span class="hlt">auroral</span> kilometric radiation can sometimes be as narrow as 5 Hz. Since this would imply an apparent source thickness of substantially less than the wavelength, it is inconsistent with the previous explanation for such discrete components based simply upon vertical localization of a cyclotron source. Instead, such narrow bandwidths can only be explained by radio lasing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....7357W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....7357W"><span id="translatedtitle">Observations of <span class="hlt">Auroral</span> Broadband Emissions by CLUSTER</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wahlund, J.-E.; et al.</p> <p>2003-04-01</p> <p>We present the results of a study based on several events of <span class="hlt">auroral</span> broadband ULF/ELF emissions observed by the CLUSTER multi-spacecraft at distances around 4-5 RE. These emissions, observed below the ion plasma frequency, have similar dispersion characteristics as the broadband emissions observed at lower altitudes (800-4000 km) by e.g. rockets (e.g. AMICIST) and satellites (e.g. FREJA and FAST). As successive passages of the four CLUSTER satellites through nearly the same regions show, the intensity of the emissions depend on the thermal properties of the plasma and gradients thereof. The total Poynting flux is downward and is comparable to energy fluxes observed at lower altitudes. We therefore believe that the broadband emissions observed by CLUSTER in the <span class="hlt">auroral</span> region are consistent with dispersed linear polarised Alfvén waves (DAW) transporting energy downward to the ionosphere guided by the magnetic field lines. These waves are therefore an important aspect for the energy transport for the <span class="hlt">auroral</span> processes leading to particle acceleration when dissipating part or all their energy along the propagation path by wave-particle coupling, causing ion heating, suprathermal electron bursts and higher frequency ion-mode waves and possibly also electric potential structures. Intermittent <span class="hlt">auroral</span> arc features have been observed embedded in a larger region of broadband emissions. The multi-spacecraft measurements by CLUSTER here show the temporal development of sharp density gradients and intensified broadband waves together with the formation of electric potential structures and particle acceleration within the larger scale density cavity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012epsc.conf..102L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012epsc.conf..102L"><span id="translatedtitle"><span class="hlt">Auroral</span> plasma acceleration processes at Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lundin, R.; Barabash, S.; Winningham, D.</p> <p>2012-09-01</p> <p>Following the first Mars Express (MEX) findings of <span class="hlt">auroral</span> plasma acceleration above Martian magnetic anomalies[1, 2], a more detailed analysis is carried out regarding the physical processes that leads to plasma acceleration, and how they connect to the dynamo-, and energy source regions. The ultimate energy source for Martian plasma acceleration is the solar wind. The question is, by what mechanisms is solar wind energy and momentum transferred into the magnetic flux tubes that connect to Martian magnetic anomalies? What are the key plasma acceleration processes that lead to aurora and the associated ionospheric plasma outflow from Mars? The experimental setup on MEX limits our capability to carry out "<span class="hlt">auroral</span> physics" at Mars. However, with knowledge acquired from the Earth, we may draw some analogies with terrestrial <span class="hlt">auroral</span> physics. Using the limited data set available, consisting of primarily ASPERA and MARSIS data, an interesting picture of aurora at Mars emerges. There are some strong similarities between accelerated/heated electrons and ions in the nightside high altitude region above Mars and the electron/ion acceleration above Terrestrial discrete aurora. Nearly monoenergetic downgoing electrons are observed in conjunction with nearly monoenergetic upgoing ions. Monoenergetic counterstreaming ions and electrons is the signature of plasma acceleration in quasi-static electric fields. However, compared to the Earth's aurora, with <span class="hlt">auroral</span> process guided by a dipole field, aurora at Mars is expected to form complex patterns in the multipole environment governed by the Martian crustal magnetic field regions. Moreover, temporal/spatial scales are different at Mars. It is therefore of interest to mention another common characteristics that exist for Earth and Mars, plasma acceleration by waves. Low-frequency, Alfvén, waves is a very powerful means of plasma acceleration in the Earth's magnetosphere. Low-frequency waves associated with plasma acceleration</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.2774B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.2774B"><span id="translatedtitle">Study of sub-<span class="hlt">auroral</span> radio emissions observed by ICE experiment onboard DEMETER satellite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boudjada, M. Y.; Galopeau, P. H. M.; Mogilevski, M. M.; Sawas, S.; Blecki, J.; Berthelier, J. J.; Voller, W.</p> <p>2012-04-01</p> <p>We report on the terrestrial kilometric and hectometric radio emissions recorded by the DEMETER/ICE (Instrument Champ Electrique) experiment. This instrument measures the electric field components of electromagnetic and electrostatic waves in the frequency range from DC to 3.25 MHz. Despite the limited satellite invariant latitude (data acquisition below about 65°), specific events have been observed, close to the sub-<span class="hlt">auroral</span> region, in the frequency range from 100 kHz to about 1 MHz. This range covers the well-known <span class="hlt">auroral</span> kilometric radiation (AKR), the terrestrial kilometric continuum, and the sub-<span class="hlt">auroral</span> terrestrial emission at higher frequency up to 3 MHz. The high spectral capability of the experiment leads us to distinguish between the bursty and the continuum emissions. Selected events have been found to principally occur in the late evening and early morning sectors of the magnetosphere (22 MLT - 02 MLT) but others have been observed on the dayside. Our first results are compared to previous radio observations performed on board INTERBALL-1 (Kuril'chik et al, Cosmic <span class="hlt">Research</span>, 43, 2005) and GEOTAIL (Hashimoto et al., JGR, 104, 1999) satellites. We also discuss the common and different features of the Earth and Jovian radio emissions. We emphasis on the observational parameters: the occurrence probability, the emission beam and the spectral emission types. We show that the physical interpretation of the <span class="hlt">auroral</span> phenomena needs a good knowledge of the geometric configuration of the source and observer and the reception system (antenna beam and receivers).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870013893','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870013893"><span id="translatedtitle">Weak double layers in the <span class="hlt">auroral</span> ionosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hudson, M. K.; Crystal, T. L.; Lotko, W.; Barnes, C.</p> <p>1987-01-01</p> <p>Previous work on the evolution of weak double layers in a hydrogen plasma was extended to include H(+) and O(+) with relative drift. The relative drift between hydrogen and oxygen ions due to a quasi-static parallel electric field gives rise to a strong linear fluid instability which dominates the ion-acoustic mode at the bottom of the <span class="hlt">auroral</span> acceleration region. This ion-ion instability can modify ion distributions at lower altitudes and the subsequent nonlinear evolution of weak double layers at higher altitudes in the ion-acoustic regime. Ion hole formation can occur for smaller relative electron-ion drifts than seen in previous simulations, due to the hydrogen-oxygen two-stream instability. This results in local modification of the ion distributions in phase space, and a partial filling of the valley between the hydrogen and oxygen peaks, which would be expected at higher altitudes on <span class="hlt">auroral</span> field lines. The observed velocity diffusion does not necessarily preclude ion hole and double layer formation in hydrogen in the ion-acoustic regime. These simulation results are consistent with the experimentally measured persistence of separate hydrogen and oxygen peaks, and the observation of weak double layers above an altitude of 3000 km on <span class="hlt">auroral</span> field lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820008211','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820008211"><span id="translatedtitle">NASA <span class="hlt">research</span> <span class="hlt">activities</span> in aeropropulsion</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mccarthy, J. F., Jr.; Weber, R. J.</p> <p>1982-01-01</p> <p>NASA is responsible for advancing technologies related to air transportation. A sampling of the work at NASA's Lewis <span class="hlt">Research</span> Center aimed at improved aircraft propulsion systems is described. Particularly stressed are efforts related to reduced noise and fuel consumption of subsonic transports. Generic work in specific disciplines are reviewed including computational analysis, materials, structures, controls, diagnostics, alternative fuels, and high-speed propellers. Prospects for variable cycle engines are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920029288&hterms=Uranus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DUranus','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920029288&hterms=Uranus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DUranus"><span id="translatedtitle">Evidence of <span class="hlt">auroral</span> plasma cavities at Uranus and Neptune from radio burst observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Farrell, W. M.; Desch, M. D.; Kaiser, M. L.; Calvert, W.</p> <p>1991-01-01</p> <p>Radio bursts originating from the stronger magnetic polar regions of both Uranus and Neptune were detected by the planetary radio astronomy experiment during the Voyager 2 encounters with the planets. It has previously been demonstrated that these bursts are beamed into a broad, hollow emission pattern from their <span class="hlt">auroral</span> sources. It is now shown that the bursts at both planets also manifest similar detailed patterns, with the waves beamed into two separate and distinct radiation cones at intermediate wave frequencies. This double-cone emission pattern is predicted by relativistic cyclotron resonance theory, and application of this theory to the observed emission pattern yields the plasma density structure within the radio source region. Calculations indicate that at both Uranus and Neptune the plasma-to-cyclotron frequency ratio can drop well below 0.01 within the <span class="hlt">active</span> region. Such low values indicate that the southern <span class="hlt">auroral</span> zones at both planets contain an <span class="hlt">auroral</span> plasma cavity that is similar to that found in earth's nightside <span class="hlt">auroral</span> zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title42-vol1/pdf/CFR-2012-title42-vol1-sec2-52.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title42-vol1/pdf/CFR-2012-title42-vol1-sec2-52.pdf"><span id="translatedtitle">42 CFR 2.52 - <span class="hlt">Research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-10-01</p> <p>... 42 Public Health 1 2012-10-01 2012-10-01 false <span class="hlt">Research</span> <span class="hlt">activities</span>. 2.52 Section 2.52 Public... OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS Disclosures Without Patient Consent § 2.52 <span class="hlt">Research</span> <span class="hlt">activities</span>. (a) Patient identifying information may be disclosed for the purpose of conducting...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title42-vol1/pdf/CFR-2014-title42-vol1-sec2-52.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title42-vol1/pdf/CFR-2014-title42-vol1-sec2-52.pdf"><span id="translatedtitle">42 CFR 2.52 - <span class="hlt">Research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-10-01</p> <p>... 42 Public Health 1 2014-10-01 2014-10-01 false <span class="hlt">Research</span> <span class="hlt">activities</span>. 2.52 Section 2.52 Public... OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS Disclosures Without Patient Consent § 2.52 <span class="hlt">Research</span> <span class="hlt">activities</span>. (a) Patient identifying information may be disclosed for the purpose of conducting...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title42-vol1/pdf/CFR-2011-title42-vol1-sec2-52.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title42-vol1/pdf/CFR-2011-title42-vol1-sec2-52.pdf"><span id="translatedtitle">42 CFR 2.52 - <span class="hlt">Research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-10-01</p> <p>... 42 Public Health 1 2011-10-01 2011-10-01 false <span class="hlt">Research</span> <span class="hlt">activities</span>. 2.52 Section 2.52 Public... OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS Disclosures Without Patient Consent § 2.52 <span class="hlt">Research</span> <span class="hlt">activities</span>. (a) Patient identifying information may be disclosed for the purpose of conducting...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title42-vol1/pdf/CFR-2013-title42-vol1-sec2-52.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title42-vol1/pdf/CFR-2013-title42-vol1-sec2-52.pdf"><span id="translatedtitle">42 CFR 2.52 - <span class="hlt">Research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-10-01</p> <p>... 42 Public Health 1 2013-10-01 2013-10-01 false <span class="hlt">Research</span> <span class="hlt">activities</span>. 2.52 Section 2.52 Public... OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS Disclosures Without Patient Consent § 2.52 <span class="hlt">Research</span> <span class="hlt">activities</span>. (a) Patient identifying information may be disclosed for the purpose of conducting...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title42-vol1/pdf/CFR-2010-title42-vol1-sec2-52.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title42-vol1/pdf/CFR-2010-title42-vol1-sec2-52.pdf"><span id="translatedtitle">42 CFR 2.52 - <span class="hlt">Research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-10-01</p> <p>... 42 Public Health 1 2010-10-01 2010-10-01 false <span class="hlt">Research</span> <span class="hlt">activities</span>. 2.52 Section 2.52 Public... OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS Disclosures Without Patient Consent § 2.52 <span class="hlt">Research</span> <span class="hlt">activities</span>. (a) Patient identifying information may be disclosed for the purpose of conducting...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820019048','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820019048"><span id="translatedtitle">Global thunderstorm <span class="hlt">activity</span> <span class="hlt">research</span> survey</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coroniti, S. C.</p> <p>1982-01-01</p> <p>The published literature on the subject of the monitoring of global thunderstorm <span class="hlt">activity</span> by instrumented satellites was reviewed. A survey of the properties of selected physical parameters of the thunderstorm is presented. The concepts used by satellites to identify and to measure terrestrial lightning pulses are described. The experimental data acquired by satellites are discussed. The scientific achievements of the satellites are evaluated against the needs of scientists and the potential requirements of user agencies. The performances of the satellites are rated according to their scientific and operational achievements.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Inventors&pg=7&id=EJ924821','ERIC'); return false;" href="http://eric.ed.gov/?q=Inventors&pg=7&id=EJ924821"><span id="translatedtitle">Embedding <span class="hlt">Research</span> <span class="hlt">Activities</span> to Enhance Student Learning</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Webster, Cynthia M.; Kenney, Jacqueline</p> <p>2011-01-01</p> <p>Purpose: The purpose of this paper's novel, <span class="hlt">research</span>-oriented approach is to embed <span class="hlt">research</span>-based <span class="hlt">activities</span> in a core second-year course of a university business degree program to support and develop student <span class="hlt">research</span> capabilities. Design/methodology/approach: The design draws on Boud and Prosser's work to foster participation in a…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150021775','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150021775"><span id="translatedtitle">An Integrated Extravehicular <span class="hlt">Activity</span> <span class="hlt">Research</span> Plan</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Abercromby, Andrew F. J.; Ross, Amy J.; Cupples, J. Scott</p> <p>2016-01-01</p> <p>Multiple organizations within NASA and outside of NASA fund and participate in <span class="hlt">research</span> related to extravehicular <span class="hlt">activity</span> (EVA). In October 2015, representatives of the EVA Office, the Crew and Thermal Systems Division (CTSD), and the Human <span class="hlt">Research</span> Program (HRP) at NASA Johnson Space Center agreed on a formal framework to improve multi-year coordination and collaboration in EVA <span class="hlt">research</span>. At the core of the framework is an Integrated EVA <span class="hlt">Research</span> Plan and a process by which it will be annually reviewed and updated. The over-arching objective of the collaborative framework is to conduct multi-disciplinary cost-effective <span class="hlt">research</span> that will enable humans to perform EVAs safely, effectively, comfortably, and efficiently, as needed to enable and enhance human space exploration missions. <span class="hlt">Research</span> <span class="hlt">activities</span> must be defined, prioritized, planned and executed to comprehensively address the right questions, avoid duplication, leverage other complementary <span class="hlt">activities</span> where possible, and ultimately provide actionable evidence-based results in time to inform subsequent tests, developments and/or <span class="hlt">research</span> <span class="hlt">activities</span>. Representation of all appropriate stakeholders in the definition, prioritization, planning and execution of <span class="hlt">research</span> <span class="hlt">activities</span> is essential to accomplishing the over-arching objective. A formal review of the Integrated EVA <span class="hlt">Research</span> Plan will be conducted annually. External peer review of all HRP EVA <span class="hlt">research</span> <span class="hlt">activities</span> including compilation and review of published literature in the EVA Evidence Book is already performed annually. Coordination with stakeholders outside of the EVA Office, CTSD, and HRP is already in effect on a study-by-study basis; closer coordination on multi-year planning with other EVA stakeholders including academia is being <span class="hlt">actively</span> pursued. Details of the current Integrated EVA <span class="hlt">Research</span> Plan are presented including description of ongoing and planned <span class="hlt">research</span> <span class="hlt">activities</span> in the areas of: Benchmarking; Anthropometry and Suit Fit; Sensors; Human</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900012078','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900012078"><span id="translatedtitle">Transmission <span class="hlt">research</span> <span class="hlt">activities</span> at NASA Lewis <span class="hlt">Research</span> Center</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lewicki, D. G.</p> <p>1990-01-01</p> <p>A joint <span class="hlt">research</span> program, to advance the technology of rotorcraft transmissions, consists of analytical and experimental efforts to achieve the overall goals of reducing transmission weight and noise, while increasing life and reliability. Recent <span class="hlt">activities</span> in the areas of transmission and related component <span class="hlt">research</span> are highlighted. Current areas include specific technologies in support of military rotary wing aviation, gearing technology, transmission noise reduction studies, a recent interest in gearbox diagnostics, and advanced transmission system studies. Results of recent <span class="hlt">activities</span> are presented along with near term <span class="hlt">research</span> plans.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AGUFMSM51A0280H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007AGUFMSM51A0280H&link_type=ABSTRACT"><span id="translatedtitle">Temporal Development of <span class="hlt">Auroral</span> Acceleration Potentials: High-Altitude Evolutionary Sequences, Drivers and Consequences</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hull, A. J.; Wilber, M.; Chaston, C.; Bonnell, J.; Mozer, F.; McFadden, J.; Goldstein, M.; Fillingim, M.</p> <p>2007-12-01</p> <p>The region above the <span class="hlt">auroral</span> acceleration region is an integral part of the <span class="hlt">auroral</span> zone electrodynamic system. At these altitudes (≥ 3 Re) we find the source plasma and fields that determine acceleration processes occurring at lower altitudes, which play a key role in the transport of mass and energy into the ionosphere. Dynamic changes in these high-altitude regions can affect and/or control lower-altitude acceleration processes according to how field-aligned currents and specific plasma sources form and decay and how they are spatially distributed, and through magnetic configuration changes deeper in the magnetotail. Though much progress has been made, the time development and consequential effects of the high-altitude plasma and fields are still not fully understood. We present Cluster multi-point observations at key instances within and above the acceleration region (> 3 RE) of evolving <span class="hlt">auroral</span> arc current systems. Results are presented from events occurring under different conditions, such as magnetospheric <span class="hlt">activity</span>, associations with density depletions or gradients, and Alfvenic turbulence. A preliminary survey, primarily at or near the plasma sheet boundary, indicates quasi- static up-down current pair systems are at times associated with density depletions and other instances occur in association with density gradients. The data suggest that such quasi-static current systems may be evolving from structured Alfvenic current systems. We will discuss the temporal development of <span class="hlt">auroral</span> acceleration potentials, plasma and currents, including quasi-static system formation from turbulent systems of structured Alfvenic field-aligned currents, density depletion and constituent reorganization of the source and ionospheric plasma that transpire in such systems. Of particular emphasis is how temporal changes in magnetospheric source plasma and fields affect the development of <span class="hlt">auroral</span> acceleration potentials at lower altitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM31C4212S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM31C4212S"><span id="translatedtitle">Statistical Characteristics of MF/HF <span class="hlt">Auroral</span> Radio Emissions Emanating from the Topside Ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sato, Y.; Kumamoto, A.; Katoh, Y.; Shinbori, A.</p> <p>2014-12-01</p> <p>The terrestrial <span class="hlt">auroral</span> ionosphere is a natural emitter of electromagnetic waves in the MF/HF ranges (up to 6 MHz) as well as well-known intense <span class="hlt">auroral</span> kilometric radiation (AKR) and <span class="hlt">auroral</span> hiss in the VLF/LF ranges. We report on the statistical properties of Terrestrial Hectometric Radiation (THR), MF/HF <span class="hlt">auroral</span> radio emissions emanating from the topside ionosphere, using a long-term data set obtained from the Plasma Waves and Sounder (PWS) experiment mounted on the Akebono satellite during 2 solar cycles. THR typically occurs in either or both of two frequency bands near 1.5-2.0 MHz and 3.0-4.0 MHz, whose polarization features correspond to the L-O and R-X mode. Statistical studies using the Akebono/PWS data reveal clear bimodality in the frequency distribution of THR with two broad peaks near 1.6 MHz and 3.6 MHz and the spatial distribution of occurrence rate of THR-L (lower than 2.5 MHz) and THR-H (higher than 2.5 MHz). In the morning to postnoon sectors (3h-15h MLT), the spatial distribution of both types of THR is confined to magnetic latitudes higher than 70 deg, while during nighttime (15h-3h MLT) it spreads to lower magnetic latitudes (~ 30 deg) at higher altitudes. The explanation of this distribution is that THR is generated in the night-side <span class="hlt">auroral</span> latitudes near 1000-km altitude and propagation effect makes an emission cone. Occurrence rate of THR-L is higher than that of THR-H. The long-term Akebono/PWS data also show clear solar <span class="hlt">activity</span> dependence and seasonal variations of THR appearance; THR occurrence rate drops from a few percent during solar maxima to 0.1 percent or less during solar minima and is the highest in summer and the lowest in winter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19800069899&hterms=ibc&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dibc','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19800069899&hterms=ibc&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dibc"><span id="translatedtitle">Production of nitrous oxide in the <span class="hlt">auroral</span> D and E regions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zipf, E. C.; Prasad, S. S.</p> <p>1980-01-01</p> <p>A study of nitrous oxide formation mechanisms indicates that N2O concentrations greater than 10 to the 9th per cu cm could be produced in IBC III aurora or by lower-level <span class="hlt">activity</span> lasting for many hours, and, in favorable conditions, the N2O concentration could exceed the local nitric oxide density. An upper limit on the globally averaged N2O production rate from <span class="hlt">auroral</span> <span class="hlt">activity</span> is estimated at 2 x 10 to the 27th per second.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840058834&hterms=energy+Chemistry&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Denergy%2BChemistry','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840058834&hterms=energy+Chemistry&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Denergy%2BChemistry"><span id="translatedtitle">Nighttime <span class="hlt">auroral</span> energy deposition in the middle atmosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goldberg, R. A.; Jackman, C. H.; Barcus, J. R.; Soraas, F.</p> <p>1984-01-01</p> <p>Ionospheric rocket sounding data for eight nighttime <span class="hlt">auroral</span> events are used to characterize relativistic electron showers and their effects on atmospheric ozone. The rockets were launched from the Poker Flat <span class="hlt">Research</span> Range in Alaska and from Andoya, Norway over the period 1976-82. Energetic fluxes were always detected but were of insufficient magnitude to produce significant changes in stratospheric ozone. However, middle atmospheric energy sources were found to be dominated by relativistic electrons and X-ray bremmstrahlung, the latter from 40-55 km and the former from 55-60 km altitudes. The ionizing radiation is concluded to be a significant factor in mesospheric ion conductivity, mobility, electric field structure and analytical models for the ion-neutral chemistry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850052710&hterms=structure+atom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dstructure%2Batom','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850052710&hterms=structure+atom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dstructure%2Batom"><span id="translatedtitle"><span class="hlt">Auroral</span> zone effects on hydrogen geocorona structure and variability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moore, T. E.; Biddle, A. P.; Waite, J. H., Jr.; Killeen, T. L.</p> <p>1985-01-01</p> <p>The effect of diurnal and magnetospheric modulations on the structure of the hydrogen geocorona is analyzed on the basis of recent observations. Particular attention is given to the enhancement of neutral escape by plasma effects, including the recently observed phenomenon of low-altitude ion acceleration. It is found that, while significant fluxes of neutral H should be produced by transverse ion acceleration in the <span class="hlt">auroral</span> zone, the process is probably insufficient to account for the observed polar depletion of hydrogen atoms. Analysis of recent exospheric temperature measurements from the Dynamics Explorer-2 satellite suggest that neutral heating in and near the high latitude cusp may be the major contributor to depleted atomic hydrogen densities at high latitudes. Altitude profiles of the production rates for escaping neutral hydrogen atoms during periods of maximum, minimum, and typical solar <span class="hlt">activity</span> are provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900043490&hterms=hashimoto&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dhashimoto','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900043490&hterms=hashimoto&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dhashimoto"><span id="translatedtitle">The magnetoionic modes and propagation properties of <span class="hlt">auroral</span> radio emissions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Calvert, Wynne; Hashimoto, Kozo</p> <p>1990-01-01</p> <p>The nature of the magnetoionic wave modes which accompany the aurora is clarified here by a detailed analysis, using multiple techniques, of DE 1 <span class="hlt">auroral</span> radio observations. All four of the possible magnetoionic wave modes are found to occur, apparently emitted from two different source regions on the same <span class="hlt">auroral</span> field line. AKR originates primarily in the X mode near the electron cyclotron frequency, and is frequently also accompanied by a weaker O-mode component from the same location. The next most prominent <span class="hlt">auroral</span> emission is the W-mode <span class="hlt">auroral</span> hiss originating from altitudes always well below the DE 1 satellite at frequencies below the local cyclotron frequency. The previously reported Z-mode <span class="hlt">auroral</span> radiation was also detected, but from sources also below the satellite at the poleward edge of the cavity, and not from the expected AKR source at the cyclotron frequency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFMSM13D4201M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFMSM13D4201M&link_type=ABSTRACT"><span id="translatedtitle">Electron Precipitation Associated with Small-Scale <span class="hlt">Auroral</span> Structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Michell, R.; Samara, M.; Grubbs, G. A., II; Hampton, D. L.; Bonnell, J. W.; Ogasawara, K.</p> <p>2014-12-01</p> <p>We present results from the Ground-to-Rocket Electrons Electrodynamics Correlative Experiment (GREECE) sounding rocket mission, where we combined high-resolution ground-based <span class="hlt">auroral</span> imaging with high time-resolution precipitating electron measurements. The GREECE payload successfully launched from Poker Flat, Alaska on 03 March 2014 and reached an apogee of approximately 335 km. The narrow field-of-view <span class="hlt">auroral</span> imaging was taken from Venetie, AK, which is directly under apogee. This enabled the small-scale <span class="hlt">auroral</span> features at the magnetic footpoint of the rocket payload to be imaged in detail. The electron precipitation was measured with the Acute Precipitating Electron Spectrometer (APES) onboard the payload. Features in the electron data are matched up with their corresponding <span class="hlt">auroral</span> structures and boundaries, enabling measurement of the exact electron distributions responsible for the specific small-scale <span class="hlt">auroral</span> features. These electron distributions will then be used to infer what the potential electron acceleration processes were.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AGUFMSM51D..03W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AGUFMSM51D..03W&link_type=ABSTRACT"><span id="translatedtitle">Midnight Sector Observations of <span class="hlt">Auroral</span> Omega Bands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wild, J. A.; Woodfield, E. E.; Donovan, E. F.; Fear, R. C.; Grocott, A.; Lester, M.; Fazakerley, A. N.; Lucek, E. A.; Kadokura, A.; Hosokawa, K.; Carlson, C. W.; McFadden, J. P.; Glassmeier, K.; Angelopoulos, V.; Björnsson, G.</p> <p>2010-12-01</p> <p>We present observations of <span class="hlt">auroral</span> omega bands on 28 September 2009. Although generally associated with the substorm recovery phase and typically observed in the morning sector, the omega bands presented here occurred just after expansion phase onset and were observed in the midnight sector, immediately dawnward of the onset region. The Tjörnes “Rainbow” all-sky imager, located in north-eastern Iceland, revealed that the omega bands were ˜200 km in scale and propagated eastward from the onset region at ˜0.4 km/s while a co-located ground magnetometer recorded the simultaneous passage of Ps 6 pulsations. Although somewhat smaller and slower-moving than the majority of previously reported omega bands, the observed structures were clear examples of this phenomenon, albeit in an atypical location and much earlier in the substorm cycle than is usual. During the study interval the THEMIS A and C probes provided detailed measurements of the upstream interplanetary environment while the Cluster spacecraft were located in the tail plasma sheet conjugate to the ground-based all-sky imager. Cluster observed pulsed fluxes of electrons moving parallel to the magnetic field towards the northern hemisphere <span class="hlt">auroral</span> ionosphere. Despite mapping uncertainties, there is some suggestion that keV electron fluxes in the tail were related to the <span class="hlt">auroral</span> emissions in the omega bands. We suggest that omega band formation may be linked to expansion phase onset in the midnight sector and that the finite propagation speed through post-midnight and early morning local times may account for the interpretation of omega bands as a morning sector recovery phase phenomenon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19770051675&hterms=1825&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D1825','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19770051675&hterms=1825&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D1825"><span id="translatedtitle">The angular distribution of <span class="hlt">auroral</span> kilometric radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Green, J. L.; Gurnett, D. A.; Shawhan, S. D.</p> <p>1977-01-01</p> <p>A study based on data from Hawkeye 1, Imp 6 and Imp 8 satellites has shown that the intense kilometric radio emissions generated over the nightside <span class="hlt">auroral</span> regions are beamed into a cone-shaped region whose axis of symmetry is tilted away from the magnetic axis of the earth, toward evenings, by about 20 deg. The solid angle of this emission cone increases systematically with increasing frequency, varying from about 1.1 sr at 56.2 kHz to about 3.5 sr at 178 kHz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.4522G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.4522G"><span id="translatedtitle">Vlasov simulations of <span class="hlt">auroral</span> flux tubes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gunell, Herbert; De Keyser, Johan; Mann, Ingrid</p> <p>2013-04-01</p> <p>Electric fields that are parallel to the earth's magnetic field are known to exist in the <span class="hlt">auroral</span> zone, where they contribute to the acceleration of <span class="hlt">auroral</span> electrons. Thus, parallel electric fields form an integral part of the <span class="hlt">auroral</span> current circuit. Transverse electric fields at high altitude result in parallel electric fields as a consequence of the closure of the field-aligned currents through the conducting ionosphere (L. R. Lyons, JGR, vol. 85, 1724, 1980). These parallel electric fields can be supported by the magnetic mirror field (Alfvén and Fälthammar, Cosmical Electrodynamics, 2nd ed., 1963). The current-voltage characteristics of an <span class="hlt">auroral</span> flux tube has been studied using stationary kinetic models (Knight, Planet. and Space Sci., vol. 21, 741-750, 1973). Observations have shown that field-aligned potential drops often are concentrated in electric double layers (e.g. Ergun, et al., Phys. Plasmas, vol. 9, 3685-3694, 2002). In the upward current region, 20-50% of the total potential drop has been identified as localised. How the rest of the potential is spread out as function of altitude is not yet known from observations (Ergun et al., J. Geophys. Res., vol. 109, A12220, doi:101.1029/2004JA010545, 2004). We have performed Vlasov simulations, using a model that is one-dimensional in configuration space and two-dimensional in velocity space. In the upward current region, most of the potential drop is found in a thin, stationary, double layer. The rest is in a region, which extends a few earth radii above it. The current-voltage characteristic approximately follows the Knight relation. The altitude of the double layer decreases with an increasing field-aligned potential drop. In the downward current region, the voltage is significantly lower than in the upward current region for the same value of the current. Double layers have been observed also in the downward current region (Andersson et al., Phys. Plasmas, vol. 9, 3600-3609, doi:10</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850034314&hterms=hasegawa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dhasegawa','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850034314&hterms=hasegawa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dhasegawa"><span id="translatedtitle">Kinetic Alfven waves on <span class="hlt">auroral</span> field lines</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goertz, C. K.</p> <p>1984-01-01</p> <p>It is suggested on the basis of several observations of Alfven waves near <span class="hlt">auroral</span> arcs that kinetic Alfven waves play a significant role in the process of particle acceleration. The characteristic properties of kinetic Alfven waves are summarized according to the theoretical classifications provided by Hasegawa and Mima (1979). The resonant coupling of large-scale surface waves to kinetic Alfven waves is also discussed. It is shown that kinetic Alfven waves can explain observations of what have previously been known as 'electrostatic' shocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM41B..06N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM41B..06N"><span id="translatedtitle">Local Geomagnetic Indices and the Prediction of <span class="hlt">Auroral</span> Power</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Newell, P. T.; Gjerloev, J. W.</p> <p>2014-12-01</p> <p>As the number of magnetometer stations and data processing power increases, just how <span class="hlt">auroral</span> power relates to geomagnetic observations becomes a quantitatively more tractable question. This paper compares Polar UVI <span class="hlt">auroral</span> power observations during 1997 with a variety of geomagnetic indices. Local time (LT) versions of the SuperMAG <span class="hlt">auroral</span> electojet (SME) are introduced and examined, along with the corresponding upper and lower envelopes (SMU and SML). Also, the East-West component, BE, is investigated. We also consider whether using any of the local indices is actually better at predicting local <span class="hlt">auroral</span> power than a single global index. Each index is separated into 24 LT indices based on a sliding 3-h MLT window. The ability to predict - or better reconstruct - <span class="hlt">auroral</span> power varies greatly with LT, peaking at 1900 MLT, where about 75% of the variance (r2) can be predicted at 1-min cadence. The aurora is fairly predictable from 1700 MLT - 0400 MLT, roughly the region in which substorms occur. <span class="hlt">Auroral</span> power is poorly predicted from <span class="hlt">auroral</span> electrojet indices from 0500 MLT - 1500 MLT, with the minima at 1000-1300 MLT. In the region of high predictability, the local variable which works best is BE, in contrast to long-standing expectations. However using global SME is better than any local variable. <span class="hlt">Auroral</span> power is best predicted by combining global SME with a local index: BE from 1500-0200 MLT, and either SMU or SML from 0300-1400 MLT. In the region of the diffuse aurora, it is better to use a 30 min average than the cotemporaneous 1-min SME value, while from 1500-0200 MLT the cotemporaneous 1-min SME works best, suggesting a more direct physical relationship with the <span class="hlt">auroral</span> circuit. These results suggest a significant role for discrete <span class="hlt">auroral</span> currents closing locally with Pedersen currents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19190567','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19190567"><span id="translatedtitle">Connecting <span class="hlt">active</span> living <span class="hlt">research</span> and public policy: transdisciplinary <span class="hlt">research</span> and policy interventions to increase physical <span class="hlt">activity</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schilling, Joseph M; Giles-Corti, Billie; Sallis, James F</p> <p>2009-01-01</p> <p>National and international organizations recommend creation of environments that support physical <span class="hlt">activity</span> where people live, work, play, study, and travel. Policy changes can lead to <span class="hlt">activity</span>-supportive environments and incentives. <span class="hlt">Research</span> on environmental and policy influences on physical <span class="hlt">activity</span> is well underway in many countries. An important use of the <span class="hlt">research</span> is to inform policy debates, but the "translation" of <span class="hlt">research</span> to policy is an emerging science. The papers in this supplement were presented at the 2008 <span class="hlt">Active</span> Living <span class="hlt">Research</span> Conference whose theme was "Connecting <span class="hlt">Active</span> Living <span class="hlt">Research</span> to Policy Solutions." The papers include evaluations of policy initiatives and <span class="hlt">research</span> that suggests promising new policies. Commentaries propose principles for improving the translation of <span class="hlt">research</span> to policy. Improving the rigor of <span class="hlt">research</span>, asking policy-relevant questions, presenting country-specific data, and effectively communicating findings to policy makers are likely to contribute to greater impact of <span class="hlt">research</span> on policy processes. PMID:19190567</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810017957','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810017957"><span id="translatedtitle">Overview of Langley <span class="hlt">activities</span> in <span class="hlt">active</span> controls <span class="hlt">research</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Abel, I.; Newsom, J. R.</p> <p>1981-01-01</p> <p>The application of <span class="hlt">active</span> controls technology to reduce aeroelastic response of aircraft structures offers a potential for significant payoffs in terms of aerodynamic efficiency and weight savings. The <span class="hlt">activities</span> of the Langley <span class="hlt">Research</span> Center (laRC) in advancing <span class="hlt">active</span> controls technology. <span class="hlt">Activities</span> are categorized into the development of appropriate analysis tools, control law synthesis methodology, and experimental investigations aimed at verifying both analysis and synthesis methodology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970027652','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970027652"><span id="translatedtitle">Geotail Measurements Compared with the Motions of High-Latitude <span class="hlt">Auroral</span> Boundaries during Two Substorms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maynard, N. C.; Burke, W. J.; Erickson, G. M.; Nakamura, M.; Mukai, T.; Kokubun, S.; Yamamoto, T.; Jacobsen, B.; Egeland, A.; Samson, J. C.; Weimer, D. R.; Reeves, G. D.; Luhr, H.</p> <p>1997-01-01</p> <p>Geotail plasma and field measurements at -95 R(sub E) are compared with extensive ground-based, near-Earth, and geosynchronous measurements to study relationships between <span class="hlt">auroral</span> <span class="hlt">activity</span> and magnetotail dynamics during the expansion phases of two substorms. The studied intervals are representative of intermittent, moderate <span class="hlt">activity</span>. The behavior of the aurora and the observed effects at Geotail for both events are harmonized by the concept of the <span class="hlt">activation</span> of near-Earth X lines (NEXL) after substorm onsets, with subsequent discharges of one or more plasmoids down the magnetotail. The plasmoids must be viewed as three-dimensional structures which are spatially limited in the dawn-dusk direction. Also, reconnection at the NEXL must proceed at variable rates on closed magnetic field lines for significant times before beginning to reconnect lobe flux. This implies that the plasma sheet in the near-Earth magnetotail is relatively thick in comparison with an embedded current sheet and that both the NEXL and distant X line can be <span class="hlt">active</span> simultaneously. Until reconnection at the NEXL engages lobe flux, the distant X line maintains control of the poleward <span class="hlt">auroral</span> boundary. If the NEXL remains <span class="hlt">active</span> after reaching the lobe, the <span class="hlt">auroral</span> boundary can move poleward explosively. The dynamics of high-latitude aurora in the midnight region thus provides a means for monitoring these processes and indicating when significant lobe flux reconnects at the NEXL.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=37858&keyword=IRST&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=76243092&CFTOKEN=95388106','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=37858&keyword=IRST&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=76243092&CFTOKEN=95388106"><span id="translatedtitle">EPA'S <span class="hlt">RESEARCH</span> PROGRAM IN GRANULAR <span class="hlt">ACTIVATED</span> CARBON</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p><span class="hlt">Research</span> into Granular <span class="hlt">Activated</span> Carbon (GAC) for use in drinking water treatment has a long history in the Drinking Water <span class="hlt">Research</span> Division and its predecessor organizations. tudies were conducted by the U.S. Public Health Service in the late fifties and early sixties to examine...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870049548&hterms=E-LAYER&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DE-LAYER','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870049548&hterms=E-LAYER&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DE-LAYER"><span id="translatedtitle">E and F region study of the evening sector <span class="hlt">auroral</span> oval - A Chatanika/Dynamics Explorer 2/NOAA 6 comparison</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Senior, C.; Sharber, J. R.; Winningham, J. D.; De La Beaujardiere, O.; Heelis, R. A.; Evans, D. S.; Sugiura, M.; Hoegy, W. R.</p> <p>1987-01-01</p> <p>Simultaneous data from the Chatanika radar and the DE 2 and NOAA 6 satellites are used to study the typical behavior of the winter evening-sector <span class="hlt">auroral</span> plasma during moderate and steady magnetic <span class="hlt">activity</span>. The equatorward edge of the <span class="hlt">auroral</span> E layer, of the region 2 field-aligned currents, and of the region of intense convection are colocated. The <span class="hlt">auroral</span> E layer extends several degrees south of the equatorward edge of the keV electron precipitation from the CPS. Although the main trough and ionization channel are embedded in a region of intense electric field where the plasma flows sunward at high speed, the flux tubes associated with these two features have different time histories. The midlatitude trough is located south of the region of electron precipitation, above a proton aurora. The ionization channel marks the poleward edge of the main trough and is colocated with the equatorward boundary of the electron precipitation from the central plasma sheet.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED562440.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED562440.pdf"><span id="translatedtitle"><span class="hlt">Research</span> on Mobile Learning <span class="hlt">Activities</span> Applying Tablets</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kurilovas, Eugenijus; Juskeviciene, Anita; Bireniene, Virginija</p> <p>2015-01-01</p> <p>The paper aims to present current <span class="hlt">research</span> on mobile learning <span class="hlt">activities</span> in Lithuania while implementing flagship EU-funded CCL project on application of tablet computers in education. In the paper, the quality of modern mobile learning <span class="hlt">activities</span> based on learning personalisation, problem solving, collaboration, and flipped class methods is…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160003081','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160003081"><span id="translatedtitle">Integrated Extravehicular <span class="hlt">Activity</span> Human <span class="hlt">Research</span> Plan: 2016</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Abercromby, Andrew F. J.; Ross, Amy J.; Cupples, J. Scott; Rajulu, Sudhakar; Norcross, Jason R.; Chappell, Steven P.</p> <p>2016-01-01</p> <p>Multiple organizations within NASA and outside of NASA fund and participate in <span class="hlt">research</span> related to extravehicular <span class="hlt">activity</span> (EVA). In October 2015, representatives of the EVA Office, the Crew and Thermal Systems Division (CTSD), and the Human <span class="hlt">Research</span> Program (HRP) at NASA Johnson Space Center agreed on a formal framework to improve multi-year coordination and collaboration in EVA <span class="hlt">research</span>. At the core of the framework is an Integrated EVA Human <span class="hlt">Research</span> Plan and a process by which it will be annually reviewed and updated. The over-arching objective of the collaborative framework is to conduct multi-disciplinary cost-effective <span class="hlt">research</span> that will enable humans to perform EVAs safely, effectively, comfortably, and efficiently, as needed to enable and enhance human space exploration missions. <span class="hlt">Research</span> <span class="hlt">activities</span> must be defined, prioritized, planned and executed to comprehensively address the right questions, avoid duplication, leverage other complementary <span class="hlt">activities</span> where possible, and ultimately provide actionable evidence-based results in time to inform subsequent tests, developments and/or <span class="hlt">research</span> <span class="hlt">activities</span>. Representation of all appropriate stakeholders in the definition, prioritization, planning and execution of <span class="hlt">research</span> <span class="hlt">activities</span> is essential to accomplishing the over-arching objective. A formal review of the Integrated EVA Human <span class="hlt">Research</span> Plan will be conducted annually. External peer review of all HRP EVA <span class="hlt">research</span> <span class="hlt">activities</span> including compilation and review of published literature in the EVA Evidence Report is will also continue at a frequency determined by HRP management. Coordination with stakeholders outside of the EVA Office, CTSD, and HRP is already in effect on a study-by-study basis; closer coordination on multi-year planning with other EVA stakeholders including academia is being <span class="hlt">actively</span> pursued. Details of the current Integrated EVA Human <span class="hlt">Research</span> Plan are presented including description of ongoing and planned <span class="hlt">research</span> <span class="hlt">activities</span> in the areas of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PASJ..tmp...36H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PASJ..tmp...36H"><span id="translatedtitle">Unusual rainbow and white rainbow: A new <span class="hlt">auroral</span> candidate in oriental historical sources</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hayakawa, Hisashi; Isobe, Hiroaki; Davis Kawamura, Akito; Tamazawa, Harufumi; Miyahara, Hiroko; Kataoka, Ryuho</p> <p>2016-04-01</p> <p>Solar <span class="hlt">activity</span> has been recorded as auroras or sunspots in various historical sources. These records are of great importance for investigating both long-term solar <span class="hlt">activities</span> and extremely intense solar flares. According to previous studies, they were recorded as "vapor," "cloud," or "light," especially in oriental historical sources; however, this terminology has not been discussed adequately, and remains still quite vague. In this paper, we suggest the possibility of using "unusual rainbow" and "white rainbow" as candidates of historical auroras in oriental historical sources, and examine if this is probable. This discovery will help us to make more comprehensive historical <span class="hlt">auroral</span> catalogues, and require us to add these terms to <span class="hlt">auroral</span> candidates in oriental historical sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PASJ...68...33H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016PASJ...68...33H&link_type=ABSTRACT"><span id="translatedtitle">Unusual rainbow and white rainbow: A new <span class="hlt">auroral</span> candidate in oriental historical sources</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hayakawa, Hisashi; Isobe, Hiroaki; Davis Kawamura, Akito; Tamazawa, Harufumi; Miyahara, Hiroko; Kataoka, Ryuho</p> <p>2016-06-01</p> <p>Solar <span class="hlt">activity</span> has been recorded as auroras or sunspots in various historical sources. These records are of great importance for investigating both long-term solar <span class="hlt">activities</span> and extremely intense solar flares. According to previous studies, they were recorded as "vapor," "cloud," or "light," especially in oriental historical sources; however, this terminology has not been discussed adequately, and remains still quite vague. In this paper, we suggest the possibility of using "unusual rainbow" and "white rainbow" as candidates of historical auroras in oriental historical sources, and examine if this is probable. This discovery will help us to make more comprehensive historical <span class="hlt">auroral</span> catalogues, and require us to add these terms to <span class="hlt">auroral</span> candidates in oriental historical sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5028893','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5028893"><span id="translatedtitle">Density measurements in key regions of the Earth's magnetosphere: Cusp and <span class="hlt">auroral</span> region</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Perraut, S.; de Feraudy, H.; Roux, A. ); Decreau, P.M.E. ); Paris, J. ); Matson, L. )</p> <p>1990-05-01</p> <p>Two <span class="hlt">active</span> experiments, a relaxation sounder and a mutual impedance probe, have been implemented on board Viking to determine the plasma density in the cusp region as well as in the sources of the <span class="hlt">auroral</span> kilometric radiation (AKR). When <span class="hlt">active</span> experiments are switched on in the cusp region, several plasma resonances are detected; they correspond to zero group velocity waves, indicative of a characteristic frequency of the plasma. Plasma density in the cusp proper is found to be much larger (> 100 cm{sup {minus}3} in some cases) than in the adjacent regions. An attempt is also made to estimate the respective densities and temperatures of the various components of the plasma. In contrast, <span class="hlt">auroral</span> regions are low-density regions. The <span class="hlt">active</span> sounding of the plasma by a relaxation sounder gives a resonance at f{sub uh}, which allows an estimate of the plasma density. Low-frequency whistler mode emissions are commonly observed in the night sector. Their upper cutoff frequency has often been used for estimating the plasma frequency. <span class="hlt">Active</span> experiments are used to test this method, which is shown to be valid most of the time in the high-altitude <span class="hlt">auroral</span> region, yet also sometimes misleading in other regions. Once the estimate of the density through the upper cutoff frequency of the hiss is validated, it can be used to follow with a good time resolution the sharp density variations experienced as Viking crossed AKR sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100033332','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100033332"><span id="translatedtitle">Cluster in the <span class="hlt">Auroral</span> Acceleration Region</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pickett, Jolene S.; Fazakerley, Andrew N.; Marklund, Gorun; Dandouras, Iannis; Christopher, Ivar W.; Kistler, Lynn; Lucek, Elizabeth; Masson, Arnaud; Taylor, Matthew G.; Mutel, Robert L.; Santolik, Ondrej; Bell, Timothy F.; Fung, Shing; Pottelette, Raymond; Hanasz, Jan; Schreiber, Roman; Hull, Arthur J.</p> <p>2010-01-01</p> <p>Due to a fortuitous evolution of the Cluster orbit, the Cluster spacecraft penetrated for the first time in its mission the heart of Earth's <span class="hlt">auroral</span> acceleration region (AAR) in December 2009 and January 2010. During this time a special AAR campaign was carried out by the various Cluster instrument teams with special support from ESA and NASA facilities. We present some of the first multi-spacecraft observations of the waves, particles and fields made during that campaign. The Cluster spacecraft configuration during these AAR passages was such that it allowed us to explore the differences in the signatures of waves, particles, and fields on the various spacecraft in ways not possible with single spacecraft. For example, one spacecraft was more poleward than the other three (C2), one was at higher altitude (C1), and one of them (0) followed another (C4) through the AAR on approximately the same track but delayed by three minutes. Their separations were generally on the order of a few thousand km or less and occasionally two of them were lying along the same magnetic field line. We will show some of the first analyses of the data obtained during the AAR campaign, where upward and downward current regions, and the waves specifically associated with those regions, as well as the <span class="hlt">auroral</span> cavities, were observed similarly and differently on the various spacecraft, helping us to explore the spatial, as well as the temporal, aspects of processes occurring in the AAR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120004173','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120004173"><span id="translatedtitle">DMSP Spacecraft Charging in <span class="hlt">Auroral</span> Environments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Colson, Andrew; Minow, Joseph</p> <p>2011-01-01</p> <p>The Defense Meteorological Satellite Program (DMSP) spacecraft are a series of low-earth orbit (LEO) satellites whose mission is to observe the space environment using the precipitating energetic particle spectrometer (SSJ/4-5). DMSP satellites fly in a geosynchronous orbit at approx.840 km altitude which passes through Earth s ionosphere. The ionosphere is a region of partially ionized gas (plasma) formed by the photoionization of neutral atoms and molecules in the upper atmosphere of Earth. For satellites in LEO, such as DMSP, the plasma density is usually high and the main contributors to the currents to the spacecraft are the precipitating <span class="hlt">auroral</span> electrons and ions from the magnetosphere as well as the cold plasma that constitutes the ionosphere. It is important to understand how the ionosphere and <span class="hlt">auroral</span> electrons can accumulate surface charges on satellites because spacecraft charging has been the cause of a number of significant anomalies for on-board instrumentation on high altitude spacecraft. These range from limiting the sensitivity of measurements to instrument malfunction depending on the magnitude of the potential difference over the spacecraft surface. Interactive Data Language (IDL) software was developed to process SSJ/4-5 electron and ion data and to create a spectrogram of the particles number and energy fluxes. The purpose of this study is to identify DMSP spacecraft charging events and to present a preliminary statistical analysis. Nomenclature</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993GMS....80...97K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993GMS....80...97K"><span id="translatedtitle"><span class="hlt">Auroral</span> weak double layers: A critical assessment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koskinen, Hannu E. J.; Mälkki, Anssi M.</p> <p></p> <p>Weak double layers (WDLs) were first observed in the mid-altitude <span class="hlt">auroral</span> magnetosphere in 1976 by the S3-3 satellite. The observations were confirmed by Viking in 1986, when more detailed information of these small-scale plasma structures became available. WDLs are upward moving rarefactive solitary structures with negative electric potential. The potential drop over a WDL is typically 0-1 V with electric field pointing predominantly upward. The structures are usually found in relatively weak (≤2 kV) <span class="hlt">auroral</span> acceleration regions where the field-aligned current is upward, but sometimes very small. The observations suggest that WDLs exist in regions of cool electron and ion background. Most likely the potential structures are embedded in the background ion population that may drift slowly upward. There have been several attempts for plasma physical explanation of WDLs but so far the success has not been very good. Computer simulations have been able to produce similar structures, but usually for somewhat unrealistic plasma parameters. A satisfactory understanding of the phenomenon requires consideration of the role of WDLs in the magnetosphere-ionosphere (MI) coupling, including the large-scale electric fields, both parallel and perpendicular to the magnetic field, and the Alfvén waves mediating the coupling. In this report we give a critical review of our present understanding of WDLs. We try to find out what can be safely deduced from the observations, what are just educated guesses, and where we may go wrong.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E1076K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016cosp...41E1076K&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Auroral</span> precipitation and descent of thermospheric NO</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kühl, Sven; Espy, Patrick; Hibbins, Robert; Paxton, Larry; Funke, Bernd</p> <p>2016-07-01</p> <p>Energetic particle precipitation in Auroras (E <20 keV) produces nitric oxide (NO) in the upper meso- and lower thermosphere region (UMLT). The subsequent descent of the NO produced in the UMLT to the lower meso- and upper stratosphere is referred to as the energetic particle precipitation indirect effect (EPP IE). The downwelling of NO produced in Auroras alters the chemistry of the mesosphere and upper stratosphere (e.g. by the NOx cycle) and possibly has important effects also on its dynamics. By observations of <span class="hlt">auroral</span> precipitation from SSUSI(DMSP) and measurements of NO from MIPAS(ENVISAT) and SMR(ODIN) we investigate the quantitative relation of the electron fluxes and characteristic energies of <span class="hlt">auroral</span> precipitation to the NO produced in the lower thermosphere and the subsequent downwelling of NO. Using additional ground-based (e.g. Meteor Radar, Microwave Radiometer) and satellite observations (SOFIE) we attempt to quantify the EPP IE and its impact on atmospheric chemistry and dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20125605','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20125605"><span id="translatedtitle">ISIS-II Scanning <span class="hlt">Auroral</span> Photometer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Anger, C D; Fancott, T; McNally, J; Kerr, H S</p> <p>1973-08-01</p> <p>The ISIS-II dual wavelength scanning <span class="hlt">auroral</span> photometer is designed to map the distribution of <span class="hlt">auroral</span> emissions at 5577 A and 3914 A over the portion of the dark earth visible to the spacecraft. A combination of internal electronic scanning and the natural orbital and rotational motions of the spacecraft causes a dual wavelength photometer to be scanned systematically across the earth. The data will be reproduced directly in the form of separate pictures representing emissions at each wavelength, which will be used to study the large-scale distribution and morphology of auroras, to study the ratio of 3914-A and 5577-A emissions thought to depend upon the energies of exciting particles), and to compare with results from other instruments on board the spacecraft and on the ground. The Red Line Photometer experiment on the same spacecraft is described in an accompanying paper by Shepherd et al. [Appl. Opt. 12, 1767 (1973)]. The instrument can be thought of as the photometric equivalent of an all-sky color camera which will view the aurora from above instead of below and with a much wider vantage point unobstructed by cloud and haze. In one satellite pass, the instrument will be capable of surveying (in one hemisphere) the entire polar region in which auroras normally occur. PMID:20125605</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21371305','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21371305"><span id="translatedtitle">Numerical investigation of <span class="hlt">auroral</span> cyclotron maser processes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Speirs, D. C.; Ronald, K.; McConville, S. L.; Gillespie, K. M.; Phelps, A. D. R.; Cross, A. W.; Robertson, C. W.; Whyte, C. G.; He, W.; Bingham, R.; Vorgul, I.; Cairns, R. A.; Kellett, B. J.</p> <p>2010-05-15</p> <p>When a mainly rectilinear electron beam is subject to significant magnetic compression, conservation of magnetic moment results in the formation of a horseshoe shaped velocity distribution. It has been shown that such a distribution is unstable to cyclotron emission and may be responsible for the generation of <span class="hlt">auroral</span> kilometric radiation--an intense rf emission sourced at high altitudes in the terrestrial <span class="hlt">auroral</span> magnetosphere. Particle-in-cell code simulations have been undertaken to investigate the dynamics of the cyclotron emission process in the absence of cavity boundaries with particular consideration of the spatial growth rate, spectral output and rf conversion efficiency. Computations reveal that a well-defined cyclotron emission process occurs albeit with a low spatial growth rate compared with waveguide bounded simulations. The rf output is near perpendicular to the electron beam with a slight backward-wave character reflected in the spectral output with a well defined peak at 2.68 GHz, just below the relativistic electron cyclotron frequency. The corresponding rf conversion efficiency of 1.1% is comparable to waveguide bounded simulations and consistent with the predictions of kinetic theory that suggest efficient, spectrally well defined emission can be obtained from an electron horseshoe distribution in the absence of radiation boundaries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17807729','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17807729"><span id="translatedtitle">Dark <span class="hlt">auroral</span> oval on saturn discovered in hubble space telescope ultraviolet images.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jaffel, L B; Leers, V; Sandel, B R</p> <p>1995-08-18</p> <p>Hubble Space Telescope ultraviolet images of Saturn obtained with the Faint Object Camera near 220 nanometers reveal a dark oval encircling the north magnetic pole of the planet. The opacity has an equivalent width of approximately 11 degrees in latitude and is centered around approximately 79 degrees N. The oval shape of the dark structure and its coincidence with the aurora detected by the Voyager Ultraviolet Spectrometer suggest that the aerosol formation is related to the <span class="hlt">auroral</span> <span class="hlt">activity</span>. PMID:17807729</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011epsc.conf..372K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011epsc.conf..372K"><span id="translatedtitle">Near-IR <span class="hlt">Auroral</span> Processes in the Polar Regions of Jupiter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, S. J.</p> <p>2011-10-01</p> <p>Recently, 3 micron <span class="hlt">auroral</span> emission lines of CH4, C2H2, and C2H6 from the south polar <span class="hlt">auroral</span> region of Jupiter were detected [1]. In order to understand the <span class="hlt">auroral</span> processes producing these emissions, we constructed an electron precipitation model for the <span class="hlt">auroral</span> atmosphere including H2, He, H, and the hydrocarbon molecules. We present preliminary results for the mixing ratios of these molecules in the stratosphere, which are consistent with the observed <span class="hlt">auroral</span> emission intensities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7248622','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7248622"><span id="translatedtitle">Determining the source region of <span class="hlt">auroral</span> emissions in the prenoon oval using coordinated Polar BEAR UV-imaging and DMSP particle measurements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Newell, P.T.; Meng, C.I. ); Huffman, R.E. )</p> <p>1992-08-01</p> <p>The Polar Beacon Experiment and <span class="hlt">Auroral</span> <span class="hlt">Research</span> (Polar BEAR) satellite included the capability for imaging the dayside <span class="hlt">auroral</span> oval in full sunlight at several wavelengths. The authors compare particle observations from the DMSP F7 satellite during dayside <span class="hlt">auroral</span> oval crossings with approximately simultaneous Polar BEAR 1,356-{angstrom} images to determine the magnetospheric source region of the dayside <span class="hlt">auroral</span> oval. The source region is determined from the Defense Meteorological Satellite Program (DMSP) particle data, according to recent work concerning the classification and identification of precipitation source regions. The close DMSP/Polar BEAR coincidences all occur when the former satellite is located between 0945 and 1,000 MLT. The authors found instances of <span class="hlt">auroral</span> arcs mapping to each of several different regions, including the boundary plasma sheet, the low-latitude boundary layer, and the plasma mantle. However, the results indicate that about half the time the most prominent <span class="hlt">auroral</span> arcs are located at the interfaces between distinct plasma regions, at least at the local time studied here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820063782&hterms=conductance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dconductance','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820063782&hterms=conductance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dconductance"><span id="translatedtitle">Precipitating electron energy flux and <span class="hlt">auroral</span> zone conductances - An empirical model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spiro, R. W.; Reiff, P. H.; Maher, L. J., Jr.</p> <p>1982-01-01</p> <p>Data from the low energy electron (LEE) experiments on the Atmosphere Explorer C and D satellites have been used to determine the average global distribution of the energy flux of precipitating <span class="hlt">auroral</span> electrons and their average energy for different levels of geomagnetic <span class="hlt">activity</span>. Measurements from the Atmosphere Explorer unified abstract file (15-s resolution) have been binned according to invariant latitude (in the range 50-90 deg), magnetic local time, and geomagnetic <span class="hlt">activity</span> as measured by the Kp and <span class="hlt">auroral</span> electrojet (AE) indices, separately. Bin-averaged values of precipitating energy flux and average energy have been calculated, and a smoothing algorithm used to reduce stochastic variations in the raw data. The results indicate that, for the parameters studied, the AE inces does a superior job of ordering the data with regard to geomagnetic <span class="hlt">activity</span>. The global distribution of the <span class="hlt">auroral</span> enhancement porition of the Pedersen and Hall conductances were inferred from the data by means of an empirical fit to detailed energy deposition calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830053141&hterms=Park+Tecnologico&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPark%2BTecnologico','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830053141&hterms=Park+Tecnologico&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPark%2BTecnologico"><span id="translatedtitle">Excitation of whistler waves by reflected <span class="hlt">auroral</span> electrons</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wu, C. S.; Dillenburg, D.; Ziebell, L. F.; Freund, H. P.</p> <p>1983-01-01</p> <p>Excitation of electron waves and whistlers by reflected <span class="hlt">auroral</span> electrons which possess a loss-cone distribution is investigated. Based on a given magnetic field and density model, the instability problem is studied over a broad region along the <span class="hlt">auroral</span> field lines. This region covers altitudes ranging from one quarter of an earth radius to five earth radii. It is found that the growth rate is significant only in the region of low altitude, say below the source region of the <span class="hlt">auroral</span> kilometric radiation. In the high altitude region the instability is insignificant either because of low refractive indices or because of small loss cone angles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850061904&hterms=direction+arrival&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddirection%2Barrival','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850061904&hterms=direction+arrival&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddirection%2Barrival"><span id="translatedtitle">The <span class="hlt">auroral</span> kilometric radiation - DE 1 direction finding studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mellott, M. M.; Huff, R. L.; Gurnett, D. A.</p> <p>1985-01-01</p> <p>The directions of arrival of <span class="hlt">auroral</span> kilometric radiation have been determined during three separate intervals using data from the DE 1 plasma wave instrument. In the case of the dominant extraordinary mode component, these directions were consistent with generation at the local electron cyclotron frequency on nightside <span class="hlt">auroral</span> field lines. The ordinary mode component appeared to have a similar source in one case, but in other cases came from different directions. These other cases were consistent with reflection at the plasmapause and the wall of the <span class="hlt">auroral</span> plasma cavity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987AdSpR...7...95N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987AdSpR...7...95N"><span id="translatedtitle">An overview of Japanese CELSS <span class="hlt">research</span> <span class="hlt">activities</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nitta, Keiji</p> <p></p> <p>Many <span class="hlt">research</span> <span class="hlt">activities</span> regarding Controlled Ecological Life Support System (CELSS) have been conducted and continued all over the world since the 1960's and the concept of CELSS is now changing from Science Fiction to Scientific Reality. Development of CELSS technology is inevitable for future long duration stays of human beings in space, for lunar base construction and for manned mars flight programs. CELSS functions can be divided into two categories, Environment Control and Material Recycling. Temperature, humidity, total atmospheric pressure and partial pressure of oxygen and carbon dioxide, necessary for all living things, are to be controlled by the environment control function. This function can be performed by technologies already developed and used as the Environment Control Life Support System (ECLSS) of Space Shuttle and Space Station. As for material recycling, matured technologies have not yet been established for fully satisfying the specific metabolic requirements of each living thing including human beings. Therefore, <span class="hlt">research</span> <span class="hlt">activities</span> for establishing CELSS technology should be focused on material recycling technologies using biological systems such as plants and animals and physico-chemical systems, for example, a gas recycling system, a water purifying and recycling system and a waste management system. Based on these considerations, Japanese <span class="hlt">research</span> <span class="hlt">activities</span> have been conducted and will be continued under the tentative guideline of CELSS <span class="hlt">research</span> <span class="hlt">activities</span> as shown in documents /1/,/2/. The status of the over all <span class="hlt">activities</span> are discussed in this paper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993AuJA....5....1S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993AuJA....5....1S&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Auroral</span> observations in the Antarctic at the time of the Tunguska event, 1908 June 30.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steel, D.; Ferguson, R.</p> <p>1993-03-01</p> <p>The original notebooks of Sir Douglas Mawson containing observations of the aurora australis by members of the British Antarctic Expedition at the time of the Tunguska explosion over Siberia on 1908 June 30 have been inspected, and it is found that, contrary to some suggestions which note that geomagnetic transients were witnessed elsewhere, and that the BAE was in winter quarters close to the south magnetic pole at the time, no exceptional <span class="hlt">auroral</span> <span class="hlt">activity</span> was seen which might have provided useful information on a planet-wide disturbance at the time of the event. However, an exceptional aurora was seen about seven hours prior to the explosion, and it is suggested that this may have been due to an anti-solar comet-like ion tail producing that <span class="hlt">auroral</span> display whilst the impactor was still far from Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AdSpR..57.2479B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AdSpR..57.2479B"><span id="translatedtitle">Intensity of the <span class="hlt">auroral</span> electrojets during a recovery phase of magnetic storm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boroyev, R. N.</p> <p>2016-06-01</p> <p>In this work, the effect of solar wind velocity on the development of magnetospheric and ionospheric disturbances is studied. It is shown that at high velocity of the solar wind during a recovery phase of magnetic storm the strong <span class="hlt">auroral</span> <span class="hlt">activity</span> characterized by the AE index is observed. In some cases during a recovery phase of magnetic storm the value of AE index is practically comparable with the value of AE index observed during the main phase of magnetic storm. When comparing time intervals of two magnetic storms during which the values of solar wind electric fields are approximately equal to each other, it is found that <span class="hlt">auroral</span> electrojet intensity is stronger in that storm in which the solar wind velocity is higher.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990042283&hterms=supplements+energy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsupplements%2Benergy','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990042283&hterms=supplements+energy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsupplements%2Benergy"><span id="translatedtitle">Global <span class="hlt">Auroral</span> Energy Deposition Compared with Magnetic Indices</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brittnacher, M. J.; Fillingim, M. O.; Elsen, R.; Parks, G. K.; Germany, G. A.; Spann, J. F., Jr.</p> <p>1997-01-01</p> <p>Measurement of the global rate of energy deposition in the ionosphere via <span class="hlt">auroral</span> particle precipitation is one of the primary goals of the Polar UVI program and is an important component of the ISTP program. The instantaneous rate of energy deposition for the entire month of January 1997 has been calculated by applying models to the UVI images and is presented by Fillingim et al. in this session. Magnetic indices, such as Kp, AE, and Dst, which are sensitive to variations in magnetospheric current systems have been constructed from ground magnetometer measurements and employed as measures of <span class="hlt">activity</span>. The systematic study of global energy deposition raises the possibility of constructing a global magnetospheric <span class="hlt">activity</span> index explicitly based on particle precipitation to supplement magnetic indices derived from ground magnetometer measurements. The relationship between global magnetic <span class="hlt">activity</span> as measured by these indices and the rate of total global energy loss due to precipitation is not known at present. We study the correlation of the traditional magnetic index of Kp for the month of January 1997 with the energy deposition derived from the UVI images. We address the question of whether the energy deposition through particle precipitation generally matches the Kp and AE indices, or the more exciting, but distinct, possibility that this particle-derived index may provide an somewhat independent measure of global magnetospheric <span class="hlt">activity</span> that could supplement traditional magnetically-based <span class="hlt">activity</span> indices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5027092','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5027092"><span id="translatedtitle">Propagation of a westward traveling surge and the development of persistent <span class="hlt">auroral</span> features</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Craven, J.D.; Frank, L.A.; Akasofu, S.I.</p> <p>1989-01-01</p> <p>Imaging instrumentation on board the spacecraft Dynamics Explorer 1 (DE 1) is used to observe the large-scale motion of a surge over 7000 km along the <span class="hlt">auroral</span> oval from near local midnight. Average speed of the surge is 2.2 km/s. Ground-based observations at Fort Yukon, Alaska, show the classical looped, multiple-arc structure of a westward traveling surge as it passes overhead. Within the 6-min temporal resolution provide with DE 1, the surge advances initially at a speed of about 8 km.s followed by a steady decline to about 1 km/s over a period of 17 min. This sequence is then repeated a second time, beginning with a significant intensification of the surge form. This intense surge <span class="hlt">activity</span> is not accompanied by significant <span class="hlt">auroral</span> <span class="hlt">activity</span> near magnetic midnight. Following passage of the surge, persistent and localized bright emission regions remain along the <span class="hlt">auroral</span> oval for several tens of minutes. Average separation distances are approximately 700 km. If these persistent features identify the sites of individual stepwise advances of the surge, the average time per advance is about 5 min.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6048596','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6048596"><span id="translatedtitle">Propagation of a westward traveling surge and the development of persistent <span class="hlt">auroral</span> features</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Craven, J.D.; Frank, L.A. ); Akasofu, S.I. )</p> <p>1989-06-01</p> <p>Imaging instrumentation on board the spacecraft Dynamics Explorer 1 (DE 1) is used to observe the large-scale motion of a surge over 7,000 km along the <span class="hlt">auroral</span> oval from near local midnight. Average speed of the surge is 2.2 km/s. Ground-based observations at Fort Yukon, Alaska, show the classical looped, multiple-arc structure of a westward traveling surge as it passes overhead. Within the 6-min temporal resolution provided with DE 1, the surge advances initially at a speed of about 8 km/s followed by a steady decline to about 1 km/s over a period of 17 min. This sequence is then repeated a second time, beginning with a significant intensification of the surge form. This intense surge <span class="hlt">activity</span> is not accompanied by significant <span class="hlt">auroral</span> <span class="hlt">activity</span> near magnetic midnight. Following passage of the surge, persistent and localized bright emission regions remain along the <span class="hlt">auroral</span> oval for several tens of minutes. Average separation distances are approximately 700 km. If these persistent features identify the sites of individual stepwise advances of the surge, the average time per advance is about 5 min.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM14A..04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM14A..04K"><span id="translatedtitle">Cassini Observations During the Saturn <span class="hlt">Auroral</span> Campaign of Spring 2013 (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kurth, W. S.; Lamy, L.; Gurnett, D. A.; Mitchell, D. G.; Dougherty, M. K.; Bunce, E. J.; Badman, S. V.; Burton, M. E.; Crary, F. J.; Pryor, W. R.; Baines, K. H.; Dyudina, U.; Nichols, J. D.; Stallard, T.; Luhmann, J. G.; Zheng, Y.; Hansen, K. C.</p> <p>2013-12-01</p> <p>During April and May 2013, a concerted effort to study Saturn's auroras was mounted using multi-wavelength observations from Cassini and a number of Earth-based observations. This paper will focus on the Cassini observations acquired during the campaign with an emphasis on the fields and particle observations and Saturn Kilometric Radiation, in particular. It has been shown that the integrated power of Saturn Kilometric Radiation (SKR) provides a good proxy for <span class="hlt">auroral</span> <span class="hlt">activity</span> and there is at least a qualitative correlation between <span class="hlt">auroral</span> brightness and SKR intensity. While the SKR observations can be complicated by beaming issues, they provide a reasonable, continuous context within which to place other observations. We compare the time history of SKR intensity with models of the solar wind input based on models which propagate 1 AU observations to the distance of Saturn. Further, direction-finding measurements of the SKR reveal the source of the SKR and these can be related to Earth-based and Cassini-based observations of the auroras. In this paper we will use the SKR observations to construct the evolution of <span class="hlt">auroral</span> <span class="hlt">activity</span> and place other in situ and remote sensing observations within this context.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AnGeo..24.3365G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AnGeo..24.3365G"><span id="translatedtitle">Towards a synthesis of substorm electrodynamics: HF radar and <span class="hlt">auroral</span> observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grocott, A.; Lester, M.; Parkinson, M. L.; Yeoman, T. K.; Dyson, P. L.; Devlin, J. C.; Frey, H. U.</p> <p>2006-12-01</p> <p>At 08:35 UT on 21 November 2004, the onset of an interval of substorm <span class="hlt">activity</span> was captured in the southern hemisphere by the Far UltraViolet (FUV) instrument on board the IMAGE spacecraft. This was accompanied by the onset of Pi2 <span class="hlt">activity</span> and subsequent magnetic bays, evident in ground magnetic data from both hemispheres. Further intensifications were then observed in both the <span class="hlt">auroral</span> and ground magnetic data over the following ~3 h. During this interval the fields-of-view of the two southern hemisphere Tasman International Geospace Enviroment Radars (TIGER) moved through the evening sector towards midnight. Whilst initially low, the amount of backscatter from TIGER increased considerably during the early stages of the expansion phase such that by ~09:20 UT an enhanced dusk flow cell was clearly evident. During the expansion phase the equatorward portion of this flow cell developed into a narrow high-speed flow channel, indicative of the <span class="hlt">auroral</span> and sub-<span class="hlt">auroral</span> flows identified in previous studies (e.g. Freeman et al., 1992; Parkinson et al., 2003). At the same time, higher latitude transient flow features were observed and as the interval progressed the flow reversal region and Harang discontinuity became very well defined. Overall, this study has enabled the spatial and temporal development of many different elements of the substorm process to be resolved and placed within a simple conceptual framework of magnetospheric convection. Specifically, the detailed observations of ionospheric flows have illustrated the complex interplay between substorm electric fields and associated <span class="hlt">auroral</span> dynamics. They have helped define the distinct nature of different substorm current systems such as the traditional substorm current wedge and the more equatorward currents associated with polarisation electric fields. Additionally, they have revealed a radar signature of nightside reconnection which provides the promise of quantifying nightside reconnection in a way which has</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850013615','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850013615"><span id="translatedtitle"><span class="hlt">Research</span> and technology <span class="hlt">activities</span> at Ames <span class="hlt">Research</span> Center's Biomedical <span class="hlt">Research</span> Division</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Martello, N.</p> <p>1985-01-01</p> <p>Various <span class="hlt">research</span> and technology <span class="hlt">activities</span> at Ames <span class="hlt">Research</span> Center's Biomedical <span class="hlt">Research</span> Division are described. Contributions to the Space Administration's goals in the life sciences include descriptions of <span class="hlt">research</span> in operational medicine, cardiovascular deconditioning, motion sickness, bone alterations, muscle atrophy, fluid and electrolyte changes, radiation effects and protection, behavior and performance, gravitational biology, and life sciences flight experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890051543&hterms=conductance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dconductance','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890051543&hterms=conductance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dconductance"><span id="translatedtitle">A comparison of ionospheric conductances and <span class="hlt">auroral</span> luminosities observed simultaneously with the Chatanika radar and the DE 1 <span class="hlt">auroral</span> imagers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Robinson, R. M.; Vondrak, R. R.; Craven, J. D.; Frank, L. A.; Miller, K.</p> <p>1989-01-01</p> <p><span class="hlt">Auroral</span> luminosities at vacuum ultraviolet (VUV) wavelengths are combined with simultaneous and coincident ionospheric electron density measurements made by the Chatanika radar to relate ionospheric conductances to optical emissions. The <span class="hlt">auroral</span> luminosities are obtained along the magnetic meridian through Chatanika with the <span class="hlt">auroral</span> imaging photometers on the Dynamics Explorer 1 satellite as the radar scans in the magnetic meridian to measure electron density and conductivity as a function of altitude and latitude. The observations are used to determine an empirical relationship between the luminosities measured at VUV wavelengths and the Hall and Pedersen conductances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870036232&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcalvert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870036232&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcalvert"><span id="translatedtitle">Satellite interferometric measurements of <span class="hlt">auroral</span> kilometric radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baumback, M. M.; Gurnett, D. A.; Calvert, W.; Shawhan, S. D.</p> <p>1986-01-01</p> <p>The first satellite interferometric measurements of <span class="hlt">auroral</span> kilometric radiation were performed by cross-correlating the waveforms detected by the ISEE 1 and ISEE 2 spacecraft. High correlations were found for all projected baselines, with little or no tendency to decrease even for the longest baselines. For incoherent radiation, the correlation as a function of the baseline is the Fourier transform of the source brightness distribution, implying an average source region diameter for all of the bursts analyzed of less than about 10 km. For such small source diameters, the required growth rates are too large to be explained by existing incoherent theories, strongly indicating that the radiation must be coherent. For coherent radiation, an upper limit to the source region diameter can be inferred instead from the angular width of the radiation pattern. The angular width of the radiation pattern must be at least 2.5 deg, implying that the diameter of the source must be less than about 20 km.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GID.....4..515S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GID.....4..515S"><span id="translatedtitle"><span class="hlt">Auroral</span> all-sky camera calibration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sigernes, F.; Holmen, S. E.; Biles, D.; Bjørklund, H.; Chen, X.; Dyrland, M.; Lorentzen, D. A.; Baddeley, L.; Trondsen, T.; Brändström, U.; Trondsen, E.; Lybekk, B.; Moen, J.; Chernouss, S.; Deehr, C. S.</p> <p>2014-09-01</p> <p>A two-step procedure to calibrate the spectral sensitivity to visible light of <span class="hlt">auroral</span> all-sky cameras is outlined. Center pixel response is obtained by the use of a Lambertian surface and a standard 45W tungsten lamp. Screen brightness is regulated by the distance between the lamp and the screen. All-sky flat-field correction is carried out with a 1 m diameter integrating sphere. A transparent Lexan dome at the exit port of the sphere is used to simulate observing conditions at the Kjell Henriksen Observatory (KHO). A certified portable low brightness source from Keo Scientific Ltd. was used to test the procedure. Transfer lamp certificates in units of Rayleigh per Ångstrøm (R Å-1) are found to be within a relative error of 2%. An all-sky camera flat-field correction method is presented with only 6 required coefficients per channel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GI......3..241S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GI......3..241S"><span id="translatedtitle"><span class="hlt">Auroral</span> all-sky camera calibration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sigernes, F.; Holmen, S. E.; Biles, D.; Bjørklund, H.; Chen, X.; Dyrland, M.; Lorentzen, D. A.; Baddeley, L.; Trondsen, T.; Brändström, U.; Trondsen, E.; Lybekk, B.; Moen, J.; Chernouss, S.; Deehr, C. S.</p> <p>2014-12-01</p> <p>A two-step procedure to calibrate the spectral sensitivity to visible light of <span class="hlt">auroral</span> all-sky cameras is outlined. Center pixel response is obtained by the use of a Lambertian surface and a standard 45 W tungsten lamp. Screen brightness is regulated by the distance between the lamp and the screen. All-sky flat-field correction is carried out with a 1 m diameter integrating sphere. A transparent Lexan dome at the exit port of the sphere is used to simulate observing conditions at the Kjell Henriksen Observatory (KHO). A certified portable low brightness source from Keo Scientific Ltd was used to test the procedure. Transfer lamp certificates in units of Rayleigh per Ångstrøm (R/Å) are found to be within a relative error of 2%. An all-sky camera flat-field correction method is presented with only 6 required coefficients per channel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720042736&hterms=OM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DOM','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720042736&hterms=OM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DOM"><span id="translatedtitle"><span class="hlt">Auroral</span> spectrum between 1200 and 4000 angstroms.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sharp, W. E.; Rees, M. H.</p> <p>1972-01-01</p> <p>Results of spectroscopic observations of an <span class="hlt">auroral</span> event made simultaneously by airborne and satellite-borne scanning spectrometers in the wavelength region between 1200 and 4000 A. Photon emission rates of several vibrational bands of the N2, 2nd positive, Vegard-Kaplan, and Lyman-Birge-Hopfield systems, the N I lines at 1200 and 3466 A, and O I lines at 1304, 1356, and 2972 A were recorded. Model calculations of the emission rates of the observed features are found to be in reasonable agreement with the measurements. Electron impact excites the nitrogen band systems, as well as the O I 1356-A line. A spectral feature at 2150 A is tentatively identified as the (1, 0) gamma band of N O.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982GeoRL...9.1120B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982GeoRL...9.1120B"><span id="translatedtitle">Harmonic <span class="hlt">auroral</span> kilometric radiation of natural origin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benson, R. F.</p> <p>1982-09-01</p> <p>When the ISIS 1 satellite passes through the <span class="hlt">auroral</span> kilometric radiation (AKR) source region the sounder receiver often detects harmonic bands of radiation associated with the fundamental AKR band. These harmonic components were earlier attributed to a nonlinear instrumental response to the strong wide-band bursty AKR fundamental signal. Evidence is here presented that indicates that these harmonics are of natural origin, namely: (1) all the harmonic signals are sometimes observed to have nearly the same bandwidth, (2) when the fundamental signal has two components the harmonic signal sometimes corresponds to the weaker rather than the stronger component, (3) a weak harmonic can be observed to be associated with a weak fundamental, and (4) a 'harmonic' signal can be observed when there is no fundamental.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820061336&hterms=ISIS+origin&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DISIS%2Borigin','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820061336&hterms=ISIS+origin&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DISIS%2Borigin"><span id="translatedtitle">Harmonic <span class="hlt">auroral</span> kilometric radiation of natural origin</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benson, R. F.</p> <p>1982-01-01</p> <p>When the ISIS 1 satellite passes through the <span class="hlt">auroral</span> kilometric radiation (AKR) source region the sounder receiver often detects harmonic bands of radiation associated with the fundamental AKR band. These harmonic components were earlier attributed to a nonlinear instrumental response to the strong wide-band bursty AKR fundamental signal. Evidence is here presented that indicates that these harmonics are of natural origin, namely: (1) all the harmonic signals are sometimes observed to have nearly the same bandwidth, (2) when the fundamental signal has two components the harmonic signal sometimes corresponds to the weaker rather than the stronger component, (3) a weak harmonic can be observed to be associated with a weak fundamental, and (4) a 'harmonic' signal can be observed when there is no fundamental.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000053171&hterms=multidisciplinary+research&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dmultidisciplinary%2Bresearch','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000053171&hterms=multidisciplinary+research&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dmultidisciplinary%2Bresearch"><span id="translatedtitle"><span class="hlt">Research</span> <span class="hlt">Activities</span> within NASA's Morphing Program</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McGowan, Anna-Maria R.; Horta, Lucas G.; Harrison, Joycelyn S.; Raney, David L.</p> <p>2000-01-01</p> <p>In the last decade, smart technologies have become important enabling technologies that cut across traditional boundaries in science and engineering. Here smart is defined as the ability to respond to a stimulus in a predictable and reproducible manner. While multiple successes have been achieved in the laboratory, we have yet to see the general applicability of smart technologies to actual aircraft and spacecraft. The NASA Morphing program is an attempt to couple <span class="hlt">research</span> across a wide range of disciplines to integrate smart technologies into high payoff applications on aircraft and spacecraft. The program bridges <span class="hlt">research</span> in several technical disciplines and combines the effort into applications that include <span class="hlt">active</span> aerodynamic control, <span class="hlt">active</span> aeroelastic control, and vehicle performance improvement. System studies are used to assess the highest-payoff program objectives, and specific <span class="hlt">research</span> <span class="hlt">activities</span> are defined to address the technologies required for development of smart aircraft and spacecraft. This paper will discuss the overall goals of NASA's Morphing program, highlight some of the recent <span class="hlt">research</span> efforts and discuss the multidisciplinary studies that support that <span class="hlt">research</span> and some of the challenges associated with bringing the smart technologies to real applications on flight vehicles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830013407','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830013407"><span id="translatedtitle">Mirror instability and origin of morningside <span class="hlt">auroral</span> structure</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chiu, Y. T.; Schulz, M.; Fennell, J. F.; Kishi, A. M.</p> <p>1983-01-01</p> <p><span class="hlt">Auroral</span> optical imagery shows marked differences between <span class="hlt">auroral</span> features of the evening and morning sectors: the separation between diffuse and discrete auroras in the evening sector is not distinct in the morning sector, which is dominated by <span class="hlt">auroral</span> patches and multiple banded structures aligned along some direction. Plasma distribution function signatures also show marked differences: downward electron beams and inverted-V signatures prefer the evening sector, while the electron spectra on the morning sector are similar to the diffuse aurora. A theory of morningside auroras consistent with these features was constructed. The theory is based on modulation of the growth rates of electron cyclotron waves by the mirror instability, which is in turn driven by inward-convected ions that have become anisotropic. This modulation produces alternating bands of enhanced and reduced electron precipitation which approximate the observed multiple <span class="hlt">auroral</span> bands and patches of the morning sector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720029850&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dnike','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720029850&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dnike"><span id="translatedtitle">Field-aligned particle currents near an <span class="hlt">auroral</span> arc.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Choy, L. W.; Arnoldy, R. L.; Potter, W.; Kintner, P.; Cahill, L. J., Jr.</p> <p>1971-01-01</p> <p>A Nike-Tomahawk rocket equipped to measure electric and magnetic fields and charged particles from a few eV to several hundred keV energy was flown into an <span class="hlt">auroral</span> band on April 11, 1970. The purpose of this flight was to obtain evidence of the low-energy electrons and protons that constitute a field-aligned sheet current, and also to obtain the magnetic signature of such a current and the electric field in and near the <span class="hlt">auroral</span>-arc electric current system. Particular attention was given to a sudden increase in the field-aligned current associated with a prior sudden increase in the electric field and a sudden change in the magnetic field, all occurring near the edge of a visual <span class="hlt">auroral</span> arc. Data obtained are discussed and analyzed; they present an important contribution to the problem of mapping of atmospheric <span class="hlt">auroral</span> phenomena to the magnetospheric equatorial plane.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993JGR....9815373C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993JGR....9815373C"><span id="translatedtitle">Analytic model of <span class="hlt">aurorally</span> coupled magnetospheric and ionospheric electrostatic potentials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cornwall, John M.</p> <p>1993-09-01</p> <p>This paper describes modest but significant improvements on earlier studies of electrostatic potential structure in the <span class="hlt">auroral</span> region, using the adiabatic <span class="hlt">auroral</span> arc model. With certain simplifying assumptions, new analytic nonlinear solutions fully exhibiting the parametric dependence of potentials on magnetospheric (e.g., cross-tail potential) and ionospheric (e.g., recombination rate) parameters are found. No purely phenomenological parameters are introduced. The results are in reasonable agreement with observed average <span class="hlt">auroral</span> potential drops, inverted-V scale sizes, and dissipation rates. The dissipation rate is quite comparable to tail energization and transport rates and should have a major effect on tail and magnetospheric dynamics. Various relations between the cross-tail potential and <span class="hlt">auroral</span> parameters (e.g., total parallel currents and potential drops) are given which can be studied with existing data sets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5846666','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5846666"><span id="translatedtitle">Mirror instability and the origin of morningside <span class="hlt">auroral</span> structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chiu, Y.T.; Schulz, M.; Fennell, J.F.; Kishi, A.M.</p> <p>1983-05-01</p> <p><span class="hlt">Auroral</span> optical imagery shows marked differences between <span class="hlt">auroral</span> features of the evening and morning sectors: The separation between diffuse and discrete auroras in the evening sector is not distinct in the morning sector, which is dominated by <span class="hlt">auroral</span> patches and multiple banded structures aligned along some direction. Plasma distribution function signatures also show marked differences: downward electron beams and inverted-V signatures prefer the evening sector, while the electron spectra on the morning sector are similar to the diffuse aurora. We have constructed a theory of morningside auroras consistent with these features. The theory is based on modulation of the growth rates of electron cyclotron waves by the mirror instability, which is in turn driven by inward-convected ions that have become anisotropic. This modulation produces alternating bands of enhanced and reduced electron precipitation which approximate the observed multiple <span class="hlt">auroral</span> bands and patches of the morning sector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT........98K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT........98K"><span id="translatedtitle">A multi-instrument study of <span class="hlt">auroral</span> hiss at Saturn</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kopf, Andrew James</p> <p>2010-11-01</p> <p>Over the last fifty years, a multitude of spacecraft and rocket experiments have studied plasma wave emissions from Earth's <span class="hlt">auroral</span> regions. One such emission is <span class="hlt">auroral</span> hiss, a low-frequency whistler-mode wave that is produced in the <span class="hlt">auroral</span> zone. Observations from Earth-orbiting spacecraft show that <span class="hlt">auroral</span> hiss is generated by field-aligned electron beams, with the resulting plasma wave emission propagating along the resonance cone. This propagation results in <span class="hlt">auroral</span> hiss appearing as a V-shaped funnel when observed on a frequency-time spectrogram. This thesis presents the first comprehensive study of <span class="hlt">auroral</span> hiss at a planet other than Earth, using the Cassini spacecraft to study <span class="hlt">auroral</span> hiss at Saturn. NASA's Cassini spacecraft, currently in orbit around Saturn, has allowed for the first opportunity to study this emission in detail at another planet. Since 2006, the Cassini spacecraft has twice been in a series of high inclination orbits, allowing investigation and measurements of Saturnian <span class="hlt">auroral</span> phenomena. During this time, the Radio and Plasma Wave Science (RPWS) Investigation on Cassini detected low frequency whistler mode emissions propagating upward along the <span class="hlt">auroral</span> field lines, much like terrestrial <span class="hlt">auroral</span> hiss. Comparisons of RPWS data with observations from several other Cassini instruments, including the Dual-Technique Magnetometer (MAG), Magnetospheric Imaging Instrument (MIMI), and the Cassini Plasma Spectrometer (CAPS), have revealed a complete picture of this emission at Saturn. Observations from these instruments have been used to make a variety of determinations about <span class="hlt">auroral</span> hiss at Saturn. RPWS has only observed this emission when Cassini was at high-latitudes, although these observations have shown no preference for local time. Tracking the times this emission has been observed revealed a clear periodicity in the emission. Further study later revealed not one but two rotational modulations, one in each hemisphere, rotating at rates of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19940033522&hterms=data+analytic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddata%2Banalytic','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940033522&hterms=data+analytic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddata%2Banalytic"><span id="translatedtitle">Analytic model of <span class="hlt">aurorally</span> coupled magnetospheric and ionospheric electrostatic potentials</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cornwall, John M.</p> <p>1993-01-01</p> <p>This paper describes modest but significant improvements on earlier studies of electrostatic potential structure in the <span class="hlt">auroral</span> region, using the adiabatic <span class="hlt">auroral</span> arc model. With certain simplifying assumptions, new analytic nonlinear solutions fully exhibiting the parametric dependence of potentials on magnetospheric (e.g., cross-tail potential) and ionospheric (e.g., recombination rate) parameters are found. No purely phenomenological parameters are introduced. The results are in reasonable agreement with observed average <span class="hlt">auroral</span> potential drops, inverted-V scale sizes, and dissipation rates. The dissipation rate is quite comparable to tail energization and transport rates and should have a major effect on tail and magnetospheric dynamics. Various relations between the cross-tail potential and <span class="hlt">auroral</span> parameters (e.g., total parallel currents and potential drops) are given which can be studied with existing data sets.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5882778','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5882778"><span id="translatedtitle"><span class="hlt">Auroral</span>-clutter predictions for Fylingdales, England. Interim report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tsunoda, R.T.</p> <p>1991-07-01</p> <p>Radar clutter produced by <span class="hlt">auroral</span> processes in the ionospheric E layer, called <span class="hlt">auroral</span> clutter, can have severe deleterious effects on surveillance radars that operate in the subauroral regions. <span class="hlt">Auroral</span> clutter characteristics, however, are practically impossible to characterize with a statistical description because of the large number of controlling parameters. Recently, a predictive code called Comprehensive E-Region <span class="hlt">Auroral</span> Clutter (CERAC) model has been written that used knowledge of the underlying physics and semiempirical data as its basis. This is a description of the predictions of the CERAC model for a surveillance radar located at Fylingdales, England. The results include predictions of occurrence, radar cross section, and Doppler velocity, all as functions of radar elevation, azimuth, range, and time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSA51C2412H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSA51C2412H"><span id="translatedtitle">Networked high-speed <span class="hlt">auroral</span> observations combined with radar measurements for multi-scale insights</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirsch, M.; Semeter, J. L.</p> <p>2015-12-01</p> <p>Networks of ground-based instruments to study terrestrial aurora for the purpose of analyzing particle precipitation characteristics driving the aurora have been established. Additional funding is pouring into future ground-based <span class="hlt">auroral</span> observation networks consisting of combinations of tossable, portable, and fixed installation ground-based legacy equipment. Our approach to this problem using the High Speed Tomography (HiST) system combines tightly-synchronized filtered <span class="hlt">auroral</span> optical observations capturing temporal features of order 10 ms with supporting measurements from incoherent scatter radar (ISR). ISR provides a broader spatial context up to order 100 km laterally on one minute time scales, while our camera field of view (FOV) is chosen to be order 10 km at <span class="hlt">auroral</span> altitudes in order to capture 100 m scale lateral <span class="hlt">auroral</span> features. The dual-scale observations of ISR and HiST fine-scale optical observations may be coupled through a physical model using linear basis functions to estimate important ionospheric quantities such as electron number density in 3-D (time, perpendicular and parallel to the geomagnetic field).Field measurements and analysis using HiST and PFISR are presented from experiments conducted at the Poker Flat <span class="hlt">Research</span> Range in central Alaska. Other multiscale configuration candidates include supplementing networks of all-sky cameras such as THEMIS with co-locations of HiST-like instruments to fuse wide FOV measurements with the fine-scale HiST precipitation characteristic estimates. Candidate models for this coupling include GLOW and TRANSCAR. Future extensions of this work may include incorporating line of sight total electron count estimates from ground-based networks of GPS receivers in a sensor fusion problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.3639D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.3639D"><span id="translatedtitle">First light from a kilometer-baseline Scintillation <span class="hlt">Auroral</span> GPS Array</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Datta-Barua, S.; Su, Y.; Deshpande, K.; Miladinovich, D.; Bust, G. S.; Hampton, D.; Crowley, G.</p> <p>2015-05-01</p> <p>We introduce and analyze the first data from an array of closely spaced Global Positioning System (GPS) scintillation receivers established in the <span class="hlt">auroral</span> zone in late 2013 to measure spatial and temporal variations in L band signals at 100-1000 m and subsecond scales. The seven receivers of the Scintillation <span class="hlt">Auroral</span> GPS Array (SAGA) are sited at Poker Flat <span class="hlt">Research</span> Range, Alaska. The receivers produce 100 s scintillation indices and 100 Hz carrier phase and raw in-phase and quadrature-phase samples. SAGA is the largest existing array with baseline lengths of the ionospheric diffractive Fresnel scale at L band. With an initial array of five receivers, we identify a period of simultaneous amplitude and phase scintillation. We compare SAGA power and phase data with collocated 630.0 nm all-sky images of an <span class="hlt">auroral</span> arc and incoherent scatter radar electron precipitation measurements, to illustrate how SAGA can be used in multi-instrument observations for subkilometer-scale studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JASTP.140..108H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JASTP.140..108H"><span id="translatedtitle">Effect of <span class="hlt">auroral</span> substorms on the ionospheric range spread-F enhancements at high southern midlatitudes using real time vertical-sounding ionograms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hajkowicz, Lech A.</p> <p>2016-03-01</p> <p>A comprehensive study has been undertaken on the effect of magnetic substorm onsets (as deduced from the <span class="hlt">auroral</span> hourly electrojet AE-index) on the occurrence of high midlatitude (or sub-<span class="hlt">auroral</span> latitude) ionospheric range spread-F (Sr). Unlike the previous reports real-time ionograms were used in this analysis thus eliminating ambiguities stemming from the correlating secondary evidence of spread-F with <span class="hlt">auroral</span> substorms. The Australian southernmost ionosonde station Hobart (51.6°S geom.) proved to be uniquely suitable for the task as being sufficiently close to the southern <span class="hlt">auroral</span> zone. Sr was assigned in km to each hourly nighttime ionogram at two sounding frequencies: Sr1 (at 2 MHz) and Sr2 (at 6 MHz) for four months in 2002: January and June (representing southern summer and winter solstices), and March and September (representing autumn and vernal equinoxes). It is evident that the southern winter solstitial period (June) is associated with high endemic midlatitude spread-F <span class="hlt">activity</span>. All other seasons are closely linked with temporal sequences of enhanced spread-F <span class="hlt">activity</span> following substorm onsets. For the first time it was possible not only find a simultaneous occurrence pattern of these diverse phenomena but to deduce numerical characteristics of the response of midlatitude ionosphere to the global <span class="hlt">auroral</span> stimulus. Excellent case events, hitherto unpublished, are shown illustrating the presence of the AE peaks (in nT) being ahead of Sr peaks (in km) by a time shift ∆t (in h). Sr1 magnitude showed a significant correlation with the magnitudes of the preceding AE with a correlation coefficient (r) of 0.51 (probability of the occurrence by chance less than 0.01). Sr2 peaks were more sensitive to <span class="hlt">auroral</span> disturbances but were not correlated with the AE magnitude variations. The time shift (∆t) was on average 4 h with a standard deviation of 3 h. The general pattern in the occurrence of magnetic substorms and spread-F is very similar. A number of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003IAUSS...4E..58S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003IAUSS...4E..58S"><span id="translatedtitle">Heuristic Programming of Educational - <span class="hlt">Research</span> <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stoev, Alexey</p> <p></p> <p>HEURISTIC PROGRAMMING OF EDUCATIONAL - <span class="hlt">RESEARCH</span> <span class="hlt">ACTIVITY</span> OF THE STUDENTS OF ASTRONOMY AT PUBLIC ASTRONOMICAL OBSERVATORIES A.Stoev Yu. Gagarin Public Astronomical Observatory Stara Zagora Bulgaria Seeking for optimal conditions of the students’ investigation skills development is exceptionally actual task in Astronomy school at Public astronomical observatory. The didactic plan of its solving is connected with a realization of the concept of the problematic approach in astronomical education. In addition different means of astronomical educative <span class="hlt">activity</span> organization are used depending on the didactic task. In some cases they are algorithmic but in others - mainly heuristic. Educational - <span class="hlt">research</span> skills are defined as skills of scientific method use in the conditions of seeking for educational problem solving the astronomical educational - <span class="hlt">research</span> task. The influence of the system of heuristic programming didactic means on the process of teaching and the use of system of didactic means for out of the school education on astronomy aimed mainly to this <span class="hlt">activity</span> rule are analyzed. In conclusion the process of optimization of the didactic conditions for students’ self-organization during the individual or collective completion of the educational - <span class="hlt">research</span> astronomical tasks at the transition from secondary to high education.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....7867D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....7867D"><span id="translatedtitle">The anticorrelation of <span class="hlt">auroral</span> arc and Pc5 pulsation occurrence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Donovan, E.; Knudsen, D.; Rankin, R.; Baker, G.; Jackel, B.; Cogger, L.; Wallis, D.</p> <p>2003-04-01</p> <p>Using extensive data sets from the CANOPUS All-Sky Imager (ASI) and magnetometer at Gillam, Canada (manetic latitude 67 degrees), we have compiled occurrence statistics of Pc5 pulsations, and <span class="hlt">auroral</span> arcs. For our purpose, Pc5 pulsations were defined as monochromatic, quasisunsoidal magnetic perturbations, with a frequency between 1.7 and 6.7 mHz, and that underwent at least four complete cycles. <span class="hlt">Auroral</span> arcs were defined to be elongated <span class="hlt">auroral</span> features. We find, consistent with the results of previous studies, that Pc5 pulsation occurrence peaks near both the dawn and dusk meridians, and <span class="hlt">auroral</span> arc occurrence in the late evening sector, near 2300 hours MLT. We discuss the implications of these results for candidate <span class="hlt">auroral</span> mechanism, in particular those which demand time variation ( ie., the field line resonance) versus those that rely on static processes, showing examples of <span class="hlt">auroral</span> arcs which display characteristics which could be attributed to mechanisms from one or the other category. We conclude that while it is clear that field-line resonances with frequencies in the Pc5 band cause or at least modulate electron precipitation in some arcs, there are equally clearly arcs for which this is not true.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EP%26S...67..166A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EP%26S...67..166A"><span id="translatedtitle">Problems with mapping the <span class="hlt">auroral</span> oval and magnetospheric substorms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antonova, E. E.; Vorobjev, V. G.; Kirpichev, I. P.; Yagodkina, O. I.; Stepanova, M. V.</p> <p>2015-10-01</p> <p>Accurate mapping of the <span class="hlt">auroral</span> oval into the equatorial plane is critical for the analysis of aurora and substorm dynamics. Comparison of ion pressure values measured at low altitudes by Defense Meteorological Satellite Program (DMSP) satellites during their crossings of the <span class="hlt">auroral</span> oval, with plasma pressure values obtained at the equatorial plane from Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellite measurements, indicates that the main part of the <span class="hlt">auroral</span> oval maps into the equatorial plane at distances between 6 and 12 Earth radii. On the nightside, this region is generally considered to be a part of the plasma sheet. However, our studies suggest that this region could form part of the plasma ring surrounding the Earth. We discuss the possibility of using the results found here to explain the ring-like shape of the <span class="hlt">auroral</span> oval, the location of the injection boundary inside the magnetosphere near the geostationary orbit, presence of quiet <span class="hlt">auroral</span> arcs in the <span class="hlt">auroral</span> oval despite the constantly high level of turbulence observed in the plasma sheet, and some features of the onset of substorm expansion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993GMS....80...89Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993GMS....80...89Z"><span id="translatedtitle">Plasma convection and currents in the <span class="hlt">auroral</span> zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Ling; Carovillano, Robert L.</p> <p></p> <p>The work we present is based upon an analytical model of the global configuration of ionospheric plasma convection, height-integrated currents, electric fields and potentials, with emphasis upon <span class="hlt">auroral</span> zone effects. Sheet-like field-aligned-currents (FACs), located at the high- and low-latitude boundaries of the <span class="hlt">auroral</span> zone, are used to represent the region I and region II currents. Utilizing the cross-cap driving potential and the region II FACs as driving mechanisms, the familiar two-cell convection pattern and the dawn to dusk electric field within the polar cap results, along with <span class="hlt">auroral</span> electrojets and low latitude shielding. The dependence of the ionospheric convection upon the relative phase and intensity of the driving FACs is discussed, including properties such as the convection rotation and twisting in the <span class="hlt">auroral</span> zone, and potential penetration to the sub-<span class="hlt">auroral</span> latitudes. The effects of the Hall to Pedersen conductivity ratio and the degree of the <span class="hlt">auroral</span> zone conductivity enhancement on the twisting of the convection pattern and on low latitude electrical shielding are also demonstrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950036502&hterms=58&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D0.58','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950036502&hterms=58&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D0.58"><span id="translatedtitle">The source of Jovian <span class="hlt">auroral</span> hiss observed by Voyager 1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Morgan, D. D.; Gurnett, D. A.; Kurth, W. S.; Bagenal, F.</p> <p>1994-01-01</p> <p>Observations of <span class="hlt">auroral</span> hiss obtained from the Voyager 1 encounter with Jupiter have been reanalyzed. The Jovian <span class="hlt">auroral</span> hiss was observed near the inner boundary of the warm Io torus and has a low-frequency cutoff caused by propagation near the resonance cone. A simple ray tracing procedure using an offset tilted dipole of the Jovian magnetic field is used to determine possible source locations. The results obtained are consistent with two sources located symmetrically with respect to the centrifugal equator along an L shell (L approximately = 5.59) that is coincident with the boundary between the hot and cold regions of the Io torus and is located just inward of the ribbon feature observed from Earth. The distance of the sources from the centrifugal equator is approximately 0.58 +/- 0.01 R(sub J). Based on the similarity to terrestrial <span class="hlt">auroral</span> hiss, the Jovian is <span class="hlt">auroral</span> hiss is believed to be generated by beams of low energy (approximately tens to thousands of eV) electrons. The low-frequency cutoff of the <span class="hlt">auroral</span> hiss suggests that the electrons are accelerated near the inferred source region, possibly by parallel electric fields similar to those existing in the terrestrial <span class="hlt">auroral</span> regions. A field-aligned current is inferred to exist at L shells just inward of the plasma ribbon. A possible mechanism for driving this current is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA....13430M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA....13430M"><span id="translatedtitle">Wide cusp/llbl ground observations by twin high-latitude <span class="hlt">auroral</span> monitors.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Massetti, S.; Candidi, M.; Cerulli-Irelli, P.; Orsini, S.</p> <p>2003-04-01</p> <p>Northern dayside <span class="hlt">auroral</span> emission associated with cusp/LLBL plasma precipitation has been monitored for many year by means of all-sky cameras from the Svalbard, sometimes by joining meridian-scanning-photometer (MSP) observations from Svalbard and/or Greenland. The typical altitude of the dayside red auroras (about 250-300km) usually means a field-of-view of roughly 1000km of diameter, about 45° of magnetic longitude, corresponding to 3 hours MLT. Taking into account the cusp displacements driven by IMF variations, this implies that for a prolonged period of time only in few occasions the cusp/LLBL <span class="hlt">auroral</span> signatures (from 2/3 to 8 hours wide) fit entirely within the field-of-view of a single imager. In the past, this fact has reduced the possibility of comparison between optical ground observations and data from satellites (DMSP, Polar, Cluster, FAST). Starting from the present 2002/2003 winter season, we have the opportunity to combine cusp/LLBL optical observations from two digital imagers located in Ny-Ålesund (Svalbard) and Daneborg (Greenland), at about the same magnetic latitude. Our twin monitors have contiguous field-of-views and allow the monitoring of the dayside <span class="hlt">auroral</span> <span class="hlt">activity</span> over about 80° of magnetic longitude, equivalent to about 5/6 hours MLT. In the present study, we show a preliminary analysis of the first campaign of observations, concerning both the dayside cusp/LLBL phenomena and the substorm-related poleward expansion of the <span class="hlt">auroral</span> oval.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMSH51B1283B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMSH51B1283B"><span id="translatedtitle">Custom <span class="hlt">auroral</span> electrojet indices calculated by using MANGO value-added services</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bargatze, L. F.; Moore, W. B.; King, T. A.</p> <p>2009-12-01</p> <p>A set of computational routines called MANGO, Magnetogram Analysis for the Network of Geophysical Observatories, is utilized to calculate customized versions of the <span class="hlt">auroral</span> electrojet indices, AE, AL, and AU. MANGO is part of an effort to enhance data services available to users of the Heliophysics VxOs, specifically for the Virtual Magnetospheric Observatory (VMO). The MANGO value-added service package is composed of a set of IDL routines that decompose ground magnetic field observations to isolate secular, diurnal, and disturbance variations of magnetic field disturbance, station-by-station. Each MANGO subroutine has been written in modular fashion to allow "plug and play"-style flexibility and each has been designed to account for failure modes and noisy data so that the programs will run to completion producing as much derived data as possible. The capabilities of the MANGO service package will be demonstrated through their application to the study of <span class="hlt">auroral</span> electrojet current flow during magnetic substorms. Traditionally, the AE indices are calculated by using data from about twelve ground stations located at northern <span class="hlt">auroral</span> zone latitudes spread longitudinally around the world. Magnetogram data are corrected for secular variation prior to calculating the standard version of the indices but the data are not corrected for diurnal variations. A custom version of the AE indices will be created by using the MANGO routines including a step to subtract diurnal curves from the magnetic field data at each station. The custom AE indices provide more accurate measures of <span class="hlt">auroral</span> electrojet <span class="hlt">activity</span> due to isolation of the sunstorm electrojet magnetic field signiture. The improvements in the accuracy of the custom AE indices over the tradition indices are largest during the northern hemisphere summer when the range of diurnal variation reaches its maximum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..210K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..210K"><span id="translatedtitle">On the physical nature of <span class="hlt">auroral</span> breakup precursors as observed in an event on 5 March 2008</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kornilov, I. A.; Kornilova, T. A.; Golovchanskaya, I. V.</p> <p>2015-03-01</p> <p>Using coordinated THEMIS spacecraft and all-sky imager observations, we studied an <span class="hlt">auroral</span> breakup event on 5 March 2008, where <span class="hlt">auroral</span> <span class="hlt">activities</span> for 30-40 min before T 0 were all of the East-West (E-W) orientation, and found that their dynamics infers a wave process. For the event under study, there were conjunctive measurements (with 3 s time resolution) of plasma, energetic particles, magnetic B and electric E fields by four THEMIS probes, positioned approximately along the tail. The THEMIS probe measurements, bandpass-filtered in the range 12-120 s, revealed the low-frequency wave <span class="hlt">activity</span> in the considered time interval. The out-of-phase relation between variations in the magnetic and plasma pressures, along with a positive correlation between -∂ Bx/∂ t and z GSM component of ion velocity (flapping), indicated the ballooning mode. Considering the similarity of the wave-like characteristics derived from ground-based <span class="hlt">auroral</span> and THEMIS spacecraft observations, we argue that the E-W <span class="hlt">auroral</span> features preceding onset may be related to ballooning waves propagating in the plasma sheet, their wavefronts inclined at relatively small angles to the azimuthal direction. The implications for mechanisms of substorm triggering are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.3396B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.3396B"><span id="translatedtitle">Study of AKR hollow pattern characteristics at sub-<span class="hlt">auroral</span> regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boudjada, Mohammed Y.; Sawas, Sami; Galopeau, Patrick; Berthelier, Jean-Jacques; Schwingenschuh, Konrad</p> <p>2014-05-01</p> <p>The Earth's <span class="hlt">auroral</span> kilometric radiation (AKR) is expected to exhibit a hollow pattern similar to that reported for the comparable emissions from Jupiter (e.g. Jovian decametric emissions - DAM). The hollow pattern is a hollow cone beam with apex at the point of AKR emission, axis tangent to the magnetic field direction, and an opening angle of the order of 80°. The properties of the hollow cone can be derived from the so-called dynamic spectrum which displays the radiation versus the observation time and the frequency. We analyze the <span class="hlt">auroral</span> kilometric radiation recorded by the electric field experiment (ICE) onboard DEMETER micro-satellite. The dynamic spectra lead us to study the occurrence of the AKR recorded in the sub-<span class="hlt">auroral</span> regions when the micro-satellite was at altitudes of about 700 km. We address in this contribution issues concerning the characteristics (occurrence, latitude and longitude) of the AKR hollow beam and their relations to the seasonal and solar <span class="hlt">activity</span> variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AnGeo..23.1371P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AnGeo..23.1371P"><span id="translatedtitle">Interhemispheric asymmetries in the occurrence of magnetically conjugate sub-<span class="hlt">auroral</span> polarisation streams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parkinson, M. L.; Pinnock, M.; Wild, J. A.; Lester, M.; Yeoman, T. K.; Milan, S. E.; Ye, H.; Devlin, J. C.; Frey, H. U.; Kikuchi, T.</p> <p>2005-06-01</p> <p>Earthward injections of energetic ions and electrons mark the onset of magnetospheric substorms. In the inner magnetosphere (L{sim}4), the energetic ions drift westward and the electrons eastward, thereby enhancing the equatorial ring current. Wave-particle interactions can accelerate these particles to radiation belt energies. The ions are injected slightly closer to Earth in the pre-midnight sector, leading to the formation of a radial polarisation field in the inner magnetosphere. This maps to a poleward electric field just equatorward of the <span class="hlt">auroral</span> oval in the ionosphere. The poleward electric field is subsequently amplified by ionospheric feedback, thereby producing <span class="hlt">auroral</span> westward flow channels (AWFCs). In terms of electric field strength, AWFCs are the strongest manifestation of substorms in the ionosphere. Because geomagnetic flux tubes are essentially equi-potentials, similar AWFC signatures should be observed simultaneously in the Northern and Southern Hemispheres. Here we present magnetically conjugate SuperDARN radar observations of AWFC <span class="hlt">activity</span> observed in the pre-midnight sector during two substorm intervals including multiple onsets during the evening of 30 November 2002. The Northern Hemisphere observations were made with the Japanese radar located at King Salmon, Alaska (57circLambda ), and the Southern Hemisphere observations with the Tasman International Geospace Environment Radar (TIGER) located at Bruny Island, Tasmania (-55circLambda ). LANL geosynchronous satellite observations of energetic ion and electron fluxes monitored the effects of substorms in the inner magnetosphere (L{sim}6). The radar-observed AWFC <span class="hlt">activity</span> was coincident with <span class="hlt">activity</span> observed at geosynchronous orbit, as well as westward current surges in the ionosphere observed using ground-based magnetometers. The location of AWFCs with respect to the <span class="hlt">auroral</span> oval was inferred from FUV <span class="hlt">auroral</span> images recorded on board the IMAGE spacecraft. DMSP SSIES ion drift measurements</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990067275&hterms=tide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dtide','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990067275&hterms=tide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dtide"><span id="translatedtitle">Polar/Tide Observations of Field Aligned O(+) Flows at 5000 km Altitude over the <span class="hlt">Auroral</span> Regions in Comparison to UVI <span class="hlt">Auroral</span> Images</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stevenson, Benjamin Adam; Craven, Paul D.; Chandler, Michael O.; Moore, Thomas E.; Giles, Barbara L.; Parks, G. K.; Pollock, Craig J.</p> <p>1999-01-01</p> <p>Measurements of thermal O(+) ion parameters from the Thermal Ion Dynamics Experiment (TIDE) on POLAR obtained near 5000 km altitude are compared with <span class="hlt">auroral</span> images from the Ultra Violet Imager (UVI), for southern perigee passes. Ion parameters, including parallel velocity, density, and flux are combined with simultaneous <span class="hlt">auroral</span> images to investigate relationships between their properties and the structure and brightness of the <span class="hlt">auroral</span> forms. Results indicate field aligned upflowing O(+) ions over bright <span class="hlt">auroral</span> regions and downward flows over dark regions. These and other relationships will be presented for several POLAR passes when both ion measurements and <span class="hlt">auroral</span> images are observed under favorable conditions for comparison.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSA13B3994L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSA13B3994L"><span id="translatedtitle">Further Studies of Ground-Level <span class="hlt">Auroral</span> Kilometric Radiation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Labelle, J. W.; Yan, X.; Pasternak, S.; Broughton, M.; Weatherwax, A. T.; Kojima, H.; Anderson, R. R.</p> <p>2014-12-01</p> <p>Following up initial observations of coincident ground-level AKR-like signals and outgoing AKR measured with the GEOTAIL satellite [LaBelle and Anderson, Geophys. Res. Lett., L04104, doi:10.1029/2010GL046411, 2011], investigation of 2008 data from four Antarctic observatories yields 37 additional examples. The occurrence rate of the ground-level AKR-like signals peaks near 22 UT similar to that of AKR. Because the distant satellite observes AKR from many sources, and because many effects can hinder transmission of AKR from the sources to either the distant satellite or the ground, a perfect correlation between ground-level AKR-like signals and outgoing AKR at GEOTAIL is not expected, and indeed correlation analysis of the ten longest-duration events suggests an imperfect correlation with 2-3 sigma significance, although at time much better correlations occur. Statistical analysis of the existing data is therefore suggestive but not does not prove a connection between the ground-level AKR-like signals and outgoing AKR. Two other methods provide strong evidence in favor of a connection between the phenomena, however. The first full-resolution measurements of ground-level AKR using a digital receiver at South Pole Station show that its fine structure closely resembles that of AKR measured by spacecraft receivers and is completely different from that of <span class="hlt">auroral</span> hiss, the other <span class="hlt">auroral</span> emission in the kilometric wavelength range. The digital receiver also determined the polarization of the AKR-like emissions to be right-hand, implying propagation in the whistler mode in the ionosphere. A weaker form of evidence comes from considering the locations of the ground station, satellite, and <span class="hlt">active</span> aurora during coincident events. Two case studies suggest that the location of the <span class="hlt">active</span> aurora, presumed connected with the AKR sources, controls whether or not the ground station detects the AKR, or which of several ground stations detects it most strongly. Taken together, these</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title38-vol1/pdf/CFR-2014-title38-vol1-sec1-488.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title38-vol1/pdf/CFR-2014-title38-vol1-sec1-488.pdf"><span id="translatedtitle">38 CFR 1.488 - <span class="hlt">Research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... PROVISIONS Disclosures Without Patient Consent § 1.488 <span class="hlt">Research</span> <span class="hlt">activities</span>. Subject to the provisions of 38 U.S.C. 5701, 38 CFR 1.500-1.527, the Privacy Act (5 U.S.C. 552a), 38 CFR 1.575-1.584 and the following paragraphs, patient medical record information covered by §§ 1.460 through 1.499 of this part may...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5036305','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5036305"><span id="translatedtitle">TRIGA <span class="hlt">research</span> reactor <span class="hlt">activities</span> around the world</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chesworth, R.H.; Razvi, J.; Whittemore, W.L. )</p> <p>1991-11-01</p> <p>Recent <span class="hlt">activities</span> at several overseas TRIGA installations are discussed in this paper, including reactor performance, <span class="hlt">research</span> programs under way, and plans for future upgrades. The following installations are included: (1) 14,000-kW TRIGA at the Institute for Nuclear <span class="hlt">Research</span>, Pitesti, Romania; (2) 2,000-kW TRIGA Mark II at the Institute of Nuclear Technology, Dhaka, Bangladesh; (3) 3,000-kW TRIGA conversion, Philippine Nuclear <span class="hlt">Research</span> Institute, Quezon City, Philippines; and (4) other ongoing installations, including a 1,500-kW TRIGA Mark II at Rabat, Morocco, and a 1,000-kW conversion/upgrade at the Institute Asunto Nucleares, Bogota, Columbia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFMSM13D4200G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFMSM13D4200G&link_type=ABSTRACT"><span id="translatedtitle">Development of Ground-Based <span class="hlt">Auroral</span> Photometry Techniques Using In-Situ Electron Precipitation Measurements from the GREECE Mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grubbs, G. A., II; Samara, M.; Michell, R.; Hampton, D.</p> <p>2014-12-01</p> <p>The Ground-to-Rocket Electrodynamics-Electrons Correlative Experiment (GREECE) mission successfully launched from Poker Flat, Alaska on 03 March 2014 at 11:09:50 UT and reached an apogee of approximately 335 km during a luminous <span class="hlt">auroral</span> event. Multiple ground-based electron-multiplying charge-coupled device (EMCCD) imagers were positioned at Venetie, Alaska and aimed along magnetic zenith in order to observe the brightness of different <span class="hlt">auroral</span> emission lines (427.8, 557.7, and 844.6 nm with a 47 degree field of view) at the magnetic footpoint of the payload, near apogee. Emission line brightness data are presented at the footpoint of the rocket flight and correlated with electron characteristics taken by the Acute Precipitating Electron Spectrometer (APES) on-board instrument. Ratios of different <span class="hlt">auroral</span> emission lines are also compared to previously published methods and models. This <span class="hlt">research</span> aims to describe the <span class="hlt">auroral</span> emissions produced from a known precipitating electron distribution, such that we can more accurately use ground-based imaging and photometry to infer the characteristics of the precipitating electrons. These techniques can then be applied over larger scales and longer times, when only multi-spectral imaging data are available with no corresponding in situ data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM23A2214G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM23A2214G"><span id="translatedtitle">A parametric study of the propagation of <span class="hlt">auroral</span> radio emissions through <span class="hlt">auroral</span> cavities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gautier, A.; Hess, S.; Cecconi, B.; Zarka, P. M.</p> <p>2013-12-01</p> <p><span class="hlt">Auroral</span> Kilometric Radiation is the radio counterpart of the Earth's <span class="hlt">auroral</span> radiations, observed in a large domain of wavelength, from Infrared to UV and obviously in visible. It is generated at high latitude (~70°), mostly along the nightside magnetic field lines connecting to the Earth's magnetospheric tail. In-situ observations by numerous spacecraft show that the radio sources are embedded inside depleted cavities. The <span class="hlt">auroral</span> cavities contain a hot tenuous plasma (ne~1 cm-3, Te~5 keV) in a strong ambient magnetic field (fp/fc < 0.1). The mechanism of emission, the Cyclotron Maser Instability (CMI), predicts an intense X mode emission near gyromagnetic frequency preferentially perpendicular to the local magnetic field. But as the radio waves are generated inside a depleted cavity, they are refracted. The apparent beaming of the source is different from that predicted by the CMI. The characteristics of the apparent beaming of the source outside of the cavity depends on several geometrical and physical parameters of the surrounding medium, as well as the frequency of the radio wave. A ray tracing code (ARTEMIS-P), which computes the trajectories of electromagnetic waves in magnetized plasma, is use to compute the path of radio ray from the source inside the hot tenuous plasma of the cavity to the outside. We model a cylindrical plasma cavity characterized by a few parameters (width, edge and parallel gradients) and we study the effect of the cavity geometry on the beaming of AKR for several frequencies. We draw conclusions about the deterministic nature of the beaming angle of the radio emissions generated in cavities. We then extend our study to emissions from giant planets.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..11910144B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..11910144B"><span id="translatedtitle">DEMETER observations of bursty MF emissions and their relation to ground-level <span class="hlt">auroral</span> MF burst</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Broughton, M. C.; LaBelle, J.; Parrot, M.</p> <p>2014-12-01</p> <p>A survey of medium frequency (MF) electric field data from selected orbits of the Detection of Electro-Magnetic Emissions Transmitted from Earthquakes (DEMETER) spacecraft reveals 68 examples of a new type of bursty MF emissions occurring at high latitudes associated with <span class="hlt">auroral</span> phenomena. These resemble <span class="hlt">auroral</span> MF burst, a natural radio emission observed at ground level near local substorm onsets. Similar to MF burst, the bursty MF waves observed by DEMETER have broadband, impulsive frequency structure covering 1.5-3.0 MHz, amplitudes of 50-100 μV/m, an overall occurrence rate of ˜0.76% with higher occurrence during <span class="hlt">active</span> times, and strong correlation with <span class="hlt">auroral</span> hiss. The magnetic local time distribution of the MF waves observed by DEMETER shows peak occurrence rate near 18 MLT, somewhat earlier than the equivalent peak in the occurrence rate of ground level MF burst, though propagation effects and differences in the latitudes sampled by the two techniques may explain this discrepancy. Analysis of solar wind and SuperMAG data suggests that while the bursty MF waves observed by DEMETER are associated with enhanced <span class="hlt">auroral</span> <span class="hlt">activity</span>, their coincidence with substorm onset may not be as exact as that of ground level MF burst. One conjunction occurs in which MF burst is observed at Churchill, Manitoba, within 8 min of MF emissions detected by DEMETER on field lines approximately 1000 km southeast of Churchill. These observations may plausibly be associated with the same <span class="hlt">auroral</span> event detected by ground level magnetometers at several Canadian observatories. Although it is uncertain, the balance of the evidence suggests that the bursty MF waves observed with DEMETER are the same phenomenon as the ground level MF burst. Hence, theories of MF burst generation in the ionosphere, such as beam-generated Langmuir waves excited over a range of altitudes or strong Langmuir turbulence generating a range of frequencies within a narrow altitude range, need to be revisited to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/10154843','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/10154843"><span id="translatedtitle">Summary of Chernobyl followup <span class="hlt">research</span> <span class="hlt">activities</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1992-06-01</p> <p>In NUREG-1251, ``Implications of the Accident at Chernobyl for Safety Regulation of Commercial Nuclear Power Plants in the United States,`` April 1989, the NRC staff concluded that no immediate changes in NRC`s regulations regarding design or operation of US commercial reactors were needed; however, it recommended that certain issues be considered further. NRC`s Chernobyl followup <span class="hlt">research</span> program consisted of the <span class="hlt">research</span> tasks undertaken in response to the recommendations in NUREG-1251. It included 23 tasks that addressed potential lessons to be learned from the Chernobyl accident. This report presents summaries of NRC`s Chernobyl followup <span class="hlt">research</span> tasks. For each task, the Chernobyl-related issues are indicated, the work is described, and the staff`s findings and conclusions are presented. More detailed reports concerning the work are referenced where applicable. This report closes out NRC`s Chernobyl followup <span class="hlt">research</span> program as such, but additional <span class="hlt">research</span> will be conducted on some issues as needed. The report includes remarks concerning significant further <span class="hlt">activity</span> with respect to the issues addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5085288','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5085288"><span id="translatedtitle">Summary of Chernobyl followup <span class="hlt">research</span> <span class="hlt">activities</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1992-06-01</p> <p>In NUREG-1251, Implications of the Accident at Chernobyl for Safety Regulation of Commercial Nuclear Power Plants in the United States,'' April 1989, the NRC staff concluded that no immediate changes in NRC's regulations regarding design or operation of US commercial reactors were needed; however, it recommended that certain issues be considered further. NRC's Chernobyl followup <span class="hlt">research</span> program consisted of the <span class="hlt">research</span> tasks undertaken in response to the recommendations in NUREG-1251. It included 23 tasks that addressed potential lessons to be learned from the Chernobyl accident. This report presents summaries of NRC's Chernobyl followup <span class="hlt">research</span> tasks. For each task, the Chernobyl-related issues are indicated, the work is described, and the staff's findings and conclusions are presented. More detailed reports concerning the work are referenced where applicable. This report closes out NRC's Chernobyl followup <span class="hlt">research</span> program as such, but additional <span class="hlt">research</span> will be conducted on some issues as needed. The report includes remarks concerning significant further <span class="hlt">activity</span> with respect to the issues addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999APS..DPP.DI203K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999APS..DPP.DI203K"><span id="translatedtitle">Plasma waves in the inhomogeneous <span class="hlt">auroral</span> ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kintner, Paul</p> <p>1999-11-01</p> <p>Detailed observations of plasma waves in the <span class="hlt">auroral</span> ionosphere during the past decade have revealed the existence of modes which depend on inhomogeneities the order of or somewhat larger than the ion gyroradius. The <span class="hlt">auroral</span> ionosphere is the most strongly driven region of space which is conveniently accessible to space probes. The region is filled with currents, electric fields, electron beams and transversely accelerated ions. During the past decade improved instrumentation has permitted investigation of the ionospheric plasma properties down to spatial scales including the ion gyroradius. These investigations have revealed at least two novel wave modes not previously anticipated. The first wave mode is associated with cylindrical density cavities aligned along the geomagnetic field. The cavities act like resonant structures near the lower hybrid frequency and admit two classes of waves near the lower hybrid frequency. Below the lower hybrid frequency the modes are trapped and rotate in a left-hand sense. Above the lower hybrid frequency waves the modes are not trapped but rotate in a right-hand sense. The symmetry in rotation is broken by the Hall current and the sense of rotation has been confirmed with sounding rocket interferometers. The cavity wave fields also accelerate ions transversely which maintain and expand the cavity dimensions. The second wave mode is less well understood and has the phenomenological name of broad band ELF (BBELF) electric fields. The bandwidth of this mode covers the ion cyclotron frequencies (O+ and H+) and it is also associated with transversely accelerated ions but not with ionospheric density structuring. Instead these modes are associated with electron flow in field-aligned currents although the flows are sub-critical for either the ion acoustic or electrostatic ion cyclotron modes. Furthermore the frequency spectrum shows no structure at the ion cyclotron frequencies. Limited evidence suggests that these modes are shear</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140010008','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140010008"><span id="translatedtitle">Representation of the <span class="hlt">Auroral</span> and Polar Ionosphere in the International Reference Ionosphere (IRI)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bilitza, Dieter; Reinisch, Bodo</p> <p>2013-01-01</p> <p>This issue of Advances in Space <span class="hlt">Research</span> presents a selection of papers that document the progress in developing and improving the International Reference Ionosphere (IRI), a widely used standard for the parameters that describe the Earths ionosphere. The core set of papers was presented during the 2010 General Assembly of the Committee on Space <span class="hlt">Research</span> in Bremen, Germany in a session that focused on the representation of the <span class="hlt">auroral</span> and polar ionosphere in the IRI model. In addition, papers were solicited and submitted from the scientific community in a general call for appropriate papers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM53E..06G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM53E..06G"><span id="translatedtitle">Spectacular ionospheric flow structures associated with substorm <span class="hlt">auroral</span> onset</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gallardo-Lacourt, B. I.; Nishimura, Y.; Lyons, L. R.; Zou, Y.; Angelopoulos, V.; Donovan, E.; Mende, S. B.; Ruohoniemi, J.; McWilliams, K. A.; Nishitani, N.</p> <p>2013-12-01</p> <p><span class="hlt">Auroral</span> observations have shown that brightening at substorm <span class="hlt">auroral</span> onset consists of azimuthally propagating beads forming along a pre-existing arc. However, the ionospheric flow structure related to this wavy <span class="hlt">auroral</span> structure has not been previously identified. We present 2-d line-of-sight flow observations and <span class="hlt">auroral</span> images from the SuperDARN radars and the THEMIS ground-based all-sky-imager array to investigate the ionospheric flow pattern associated with the onset. We have selected events where SuperDARN was operating in the THEMIS mode, which provides measurements along the northward looking radar beam that have time resolution (6 s) comparable to the high time resolution of the imagers and gives us a unique tool to detect properties of flows associated with the substorm onset instability. We find very fast flows (~1000 m/s) that initiated simultaneously with the onset arc beads propagating across the THEMIS-mode beam meridian. The flows show oscillations at ~9 mHz, which corresponds to the periodicity of the <span class="hlt">auroral</span> beads propagating across the radar beam. 2-d radar measurements also show a wavy pattern in the azimuthal direction with a wavelength of ~74 km, which is close to the azimuthal separation of individual beads, although this determination is limited by the 2 minute radar scan period. These strong correlations (in time and space) between <span class="hlt">auroral</span> beading and the fast ionospheric flows suggest that these spectacular flows are an important feature of the substorm onset instability within the inner plasma sheet. Also, a clockwise flow shear was observed in association with individual <span class="hlt">auroral</span> beads, suggesting that such flow shear is a feature of the unstable substorm onset waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSA31E2374G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSA31E2374G"><span id="translatedtitle">Influence of <span class="hlt">auroral</span> streamers on rapid evolution of SAPS flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gallardo-Lacourt, B.; Nishimura, T.; Lyons, L. R.; Ruohoniemi, J. M.; Donovan, E.; Angelopoulos, V.; Nishitani, N.</p> <p>2015-12-01</p> <p>An important manifestation of plasma transport in the ionosphere is Subauroral Polarization Streams or SAPS, which are strong westward flow lying just equatorward of the electron <span class="hlt">auroral</span> oval and thus of enhanced ionospheric conductivities of the <span class="hlt">auroral</span> oval. While SAPS are known to intensify due to substorm injections, recent studies showed that large variability of SAPS flow can occur well after substorm onset and even during non-substorm times. These SAPS enhancements have been suggested to occur in association with <span class="hlt">auroral</span> streamers that propagate equatorward, a suggestion that would indicate that plasma sheet fast flows propagate into the inner magnetosphere and increase subauroral flows. We present <span class="hlt">auroral</span> images from the THEMIS ground-based all-sky-imager array and 2-d line-of-sight flow observations from the SuperDARN radars that share fields of view with the imagers to investigate systematically the association between SAPS and <span class="hlt">auroral</span> streamers. We surveyed events from December 2007 to April 2013 for which high or mid-latitude SuperDARN radars were available to measure the SAPS flows, and identified 60 events. For streamers observed near the equatorward boundary of the <span class="hlt">auroral</span> oval, we find westward flow enhancements of ~200 m/s slightly equatorward of the streamers. A preliminary survey suggests that >90% of the streamers that reach close to the equatorward boundary lead to westward flow enhancements. We also characterize the SAPS flow channel width and timing relative to streamers reaching radar echo meridians. The strong influence of <span class="hlt">auroral</span> streamers on rapid SAPS flow evolution suggests that transient fast earthward plasma sheet flows can lead to westward SAPS flow enhancements in the subauroral region, and that such enhancements are far more common than only during substorms because of the frequent occurrences of streamers under various geomagnetic conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000JGR...10515897F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000JGR...10515897F"><span id="translatedtitle">Observations of magnetic field dipolarization during <span class="hlt">auroral</span> substorm onset</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frank, L. A.; Paterson, W. R.; Sigwarth, J. B.; Kokubun, S.</p> <p>2000-07-01</p> <p>The dynamical behavior of plasmas and magnetic fields in the vicinity of the equatorial crossing of magnetic field lines threading the onset <span class="hlt">auroral</span> arc is examined for two substorms on November 26, 1997. The locations of the initial brightenings of the <span class="hlt">auroral</span> arcs were determined with the cameras for visible and far-ultraviolet wavelengths on board the Polar spacecraft. The equatorial positions of the field lines were in the range of radial distances of 8-12RE as computed with models of Earth's global magnetic field. The radial distance of the Geotail spacecraft was 14 RE at a position in the premidnight sector that was 2RE below the current sheet. This spacecraft was embedded in a low-β plasma that was located adjacent to the central hot plasma sheet. For the first substorm, with onset at 1310 UT, no substantial effect was observed in the plasmas and magnetic fields, although the Geotail spacecraft was located only about 2 hours in magnetic local time from the field lines threading the onset <span class="hlt">auroral</span> arc. For the second substorm onset, at 1354 UT, the spacecraft was positioned within tens of minutes in local time of the position of the magnetic field lines threading the onset <span class="hlt">auroral</span> arc. This fortuitous spacecraft position in the relatively quiescent plasma and magnetic fields adjacent to the central plasma sheet and within several Earth radii of the position of the onset mechanism allowed determination of the beginning time of the dipolarization of the magnetic fields. This time was simultaneous with the onset brightening of the <span class="hlt">auroral</span> arc within the approximately 1-min time resolution of the <span class="hlt">auroral</span> images. The simultaneity of the initial brightening of the <span class="hlt">auroral</span> arc and of the initiation of the dipolarization of the magnetic field, presumably due to diversion of current from the equatorial current sheet to the ionosphere, provides an important guideline for global dynamical MHD models of Earth's magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM23C4251G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM23C4251G"><span id="translatedtitle">Influence of <span class="hlt">auroral</span> streamers on rapid evolution of SAPS flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gallardo-Lacourt, B.; Nishimura, T.; Lyons, L. R.; Angelopoulos, V.; Donovan, E.; Ruohoniemi, J. M.; McWilliams, K. A.; Nishitani, N.</p> <p>2014-12-01</p> <p>An important manifestation of plasma transport in the ionosphere is Subauroral Polarization Streams or SAPS, which are strong westward flow lying just equatorward of the electron <span class="hlt">auroral</span> oval and thus of enhanced ionospheric conductivities of the <span class="hlt">auroral</span> oval. While SAPS are known to intensify due to substorm injections, recent studies showed that large variability of SAPS flow can occur well after substorm onset and even during non-substorm times. These SAPS enhancements have been suggested to occur in association with <span class="hlt">auroral</span> streamers that propagate equatorward and then turn azimuthally, a suggestion that would indicate that plasma sheet fast flows propagate into the inner magnetosphere and increase subauroral flows. We present <span class="hlt">auroral</span> images from the THEMIS ground-based all-sky-imager array and 2-d line-of-sight flow observations from the SuperDARN radars that share fields of view with the imagers to investigate systematically the association between SAPS and <span class="hlt">auroral</span> streamers. We surveyed events from December 2007 to April 2010 for which high or mid-latitude SuperDARN radars were available to measure the SAPS flows, and identified 30 events. For streamers observed near the equatorward boundary of the <span class="hlt">auroral</span> oval either while turning, or after having turned, westward, we find westward flow enhancements of ~200 m/s slightly equatorward of the streamers. A preliminary survey suggests that >90% of the streamers that turn westward lead to westward flow enhancements. We also characterize the SAPS flow channel width and timing relative to streamers reaching radar echo meridians. The strong influence of <span class="hlt">auroral</span> streamers on rapid evolution of SAPS flows suggests that transient fast earthward plasma sheet flows can lead to westward SAPS flow enhancements in the subauroral region, and that such enhancements are far more common than just during substorms because of the frequent occurrences of streamers under various geomagnetic conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUSM..ED21B01G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUSM..ED21B01G"><span id="translatedtitle">AGU <span class="hlt">Activities</span> to Promote Undergraduate <span class="hlt">Research</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grove, K.; Johnson, R.; Giesler, J.</p> <p>2001-05-01</p> <p>A primary goal of the AGU Committee on Education and Human Resources (CEHR) is to significantly increase the participation of undergraduate students at AGU meetings. Involving students in scientific meetings at this level of their education helps them to better prepare for graduate school and for a career in the geophysical sciences. Ongoing CEHR <span class="hlt">activities</span> to promote undergraduate participation include: (1) sponsoring technical sessions to showcase undergraduate <span class="hlt">research</span>; (2) sponsoring sessions about careers and other topics of special interest to students; (3) sponsoring workshops to inform faculty about doing <span class="hlt">research</span> with undergraduates; (4) sponsoring meeting events to partner graduate student mentors with first-time undergraduate attendees; (5) working with sections to create situations where undergraduates and section scientists can interact; (6) creating a guide for first-time meeting attendees; (7) sponsoring an Academic Recruiting Forum at meetings to connect undergraduates with geophysical graduate programs; (8) running a Career Center at meetings to connect students and employers; (9) raising funds for more travel grants to provide more student support to attend meetings; (10) developing a listserve to inform AGU members about opportunities to do <span class="hlt">research</span> with undergraduates and to involve more members in mentoring <span class="hlt">activities</span>; and (11) collecting data, such as career outcomes and demographic characteristics of recent Ph.D. recipients, that are of interest to students.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AGUFMSA44A..09H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AGUFMSA44A..09H&link_type=ABSTRACT"><span id="translatedtitle">Observations of an <span class="hlt">Auroral</span> Arc using the 4-Channel Camera on the VISIONS Rocket</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hecht, J. H.; Clemmons, J. H.; Rowland, D. E.; Pfaff, R. F.; Conde, M.; Hampton, D. L.; Michell, R.</p> <p>2013-12-01</p> <p>The VISIONS rocket, designed to study oxygen ion outflow, was launched from Poker Flat <span class="hlt">Research</span> Range at 0821 UT on February 7th 2013. It reached an altitude of over 750 km and provided useful data as far as 74 degrees north latitude well into the polar cap. One of the payload instruments was a down looking, 90 degree field of view, four channel camera (N2+1Negative(0,0), OI (630nm), OI (844.6nm) and H-Beta) to observe the <span class="hlt">auroral</span> emissions that might be the source of the outflow observed from other instruments. The camera was nominally pointed towards Arctic Village (68N) and thus on the down leg the camera had a limb view of the northern edge of the <span class="hlt">auroral</span> oval which was nominally located over a latitude that passed through Kaktovik Alaska (70 N). Considerable periods of presumably lower average energy (2 keV to less than 1 keV) electron precipitation occurred at that latitude during the 16-minute flight. The limb view at the end of the flight (approximately 880 s after launch) allowed a measure of the vertical distribution of the <span class="hlt">auroral</span> emissions. The interpretation of those images was aided by the fact that an isolated intense <span class="hlt">auroral</span> arc was located right over Kaktovik, and thus in the field of view of a ground-based imager deployed by SWRI, at the same time as the rocket camera was observing from the side the vertical distribution of the <span class="hlt">auroral</span> emission. Modeling of the rocket camera data suggest a considerable depletion of O with respect to N2 which becomes especially noticeable in the OI (630 nm) emission where the O component of the emission appears to be nearly absent. The large O depletion is presumably caused by the deposition of low energy electrons, at the northern edge of the oval, at E and F region altitudes, and the resultant production of large vertical winds during a time at or before these observations were obtained. The particle precipitation that produced the vertical winds is a scenario that should also be favorable to ion outflow and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860057116&hterms=Porcupines&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DPorcupines','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860057116&hterms=Porcupines&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DPorcupines"><span id="translatedtitle">Dynamics of a discrete <span class="hlt">auroral</span> arc</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bruening, K.; Goertz, C. K.</p> <p>1986-01-01</p> <p>Porcupine Flight 4 data were used to determine the field-aligned currents associated with a southward moving discrete <span class="hlt">auroral</span> arc in the postmidnight sector. Three different methods were used for determining the field-aligned current which should give identical results if the arcs are quasi-stationary and no parallel electric field exists between the payload and the dynamo region of the ionosphere. As long as the rocket is above the arc, the three methods agree. The integral of precipitating electron flux, the local magnetic field perturbations, and the divergence of the horizontal Pedersen current all indicate an upward current of 5 + or - 3 microamperes/sq m. Immediately north of the arc a strong downward current of about 10-20 microamperes/sq m is detected. The magnitude, however, is not well known because the rocket's velocity relative to the arc cannot be clearly established. Further north of the southward moving arc, the two methods that can be applied (magnetic field perturbations and divergence of the horizontal Pedersen current) yield contradictory results not only about the magnitude of the current but also about the direction of the current. It is suggested that this discrepancy is due to time-dependent electric field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1986JGR....91.7057B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1986JGR....91.7057B&link_type=ABSTRACT"><span id="translatedtitle">Dynamics of a discrete <span class="hlt">auroral</span> arc</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bruening, K.; Goertz, C. K.</p> <p>1986-06-01</p> <p>Porcupine Flight 4 data were used to determine the field-aligned currents associated with a southward moving discrete <span class="hlt">auroral</span> arc in the postmidnight sector. Three different methods were used for determining the field-aligned current which should give identical results if the arcs are quasi-stationary and no parallel electric field exists between the payload and the dynamo region of the ionosphere. As long as the rocket is above the arc, the three methods agree. The integral of precipitating electron flux, the local magnetic field perturbations, and the divergence of the horizontal Pedersen current all indicate an upward current of 5 + or - 3 microamperes/sq m. Immediately north of the arc a strong downward current of about 10-20 microamperes/sq m is detected. The magnitude, however, is not well known because the rocket's velocity relative to the arc cannot be clearly established. Further north of the southward moving arc, the two methods that can be applied (magnetic field perturbations and divergence of the horizontal Pedersen current) yield contradictory results not only about the magnitude of the current but also about the direction of the current. It is suggested that this discrepancy is due to time-dependent electric field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840062983&hterms=conductance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dconductance','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840062983&hterms=conductance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dconductance"><span id="translatedtitle">Models of <span class="hlt">auroral</span>-zone conductances</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reiff, P. H.</p> <p>1984-01-01</p> <p>The magnetosphere-ionosphere system is strongly coupled, with magnetospheric Birkeland currents feeding ionospheric Pedersen and Hall currents. Central to any computer simulation of this system is a detailed, valid conductivity model. An accurate conductivity model is also vital in order to infer Birkeland currents and electric field patterns from inversions of magnetometer chain data. Several recent attempts at constructing conductivity models are presented and their strengths and weaknesses discussed. Incoherent scatter radar measurements can determine height profiles of electron content, from which Pedersen and Hall conductances may be calculated. These yield excellent spatial and good temporal resolution; however, they are limited in field of view. A global pattern requires either 24 hours of data or a chain of stations. Synoptic empirical models (quantized by indices such as Kp or AE) typically are limited by their large bin size (1 deg invariant latitude x 1 hour MLT), and cannot reproduce arcs. Estimating conductivity globally from Dynamics Explorer <span class="hlt">auroral</span> images is promising, and can yield reasonable time scales (of about 10 minutes); however, this procedure is still only now being tested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AGUFMSM41A1830E&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AGUFMSM41A1830E&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Auroral</span> signatures of Bursty Bulk Flows from magnetosphere-ionosphere coupling models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Echim, M.; de Keyser, J. M.; Roth, M. A.</p> <p>2010-12-01</p> <p>The relationship between bursty bulk flows (BBFs) in the magnetospheric tail and the <span class="hlt">activation</span> of <span class="hlt">auroral</span> forms is well established from satellite and ground-based observations. Starting from a self-consistent description of BBFs based on a Vlasov equilibrium we provide a quantitative evaluation of the associated <span class="hlt">auroral</span> effects by using a quasi-stationary magnetosphere-ionosphere (MI) coupling model. The self-consistent BBF model is based on a kinetic description of a 1-D plasma slab moving in background plasma and electromagnetic field. The model considers two exact constants of motion and one adiabatic invariant (the magnetic moment). It solves the coupled Vlasov-Maxwell system of equations in one spatial dimension (perpendicular to the BBFs plasma bulk velocity and the main magnetic field) assuming the BBF is a 1D structure elongated in the direction of the background magnetic field. The BBF model provides the self-consistent profile of Φm, the electric potential, showing the formation of convergent electric fields at the dawnward flank of the Earth-ward oriented BBFs. It has been shown that magnetospheric convergent electric fields drive field-aligned (FA) potential drops, FA currents and electron precipitation and acceleration. A stationary MI coupling model developed for discontinuity-like magnetospheric generators with convergent electric fields developed earlier is adapted to describe the coupling between the BBFs and the <span class="hlt">auroral</span> ionosphere. The kernel of the MI coupling model is the condition of current continuity at the topside ionosphere, from which we compute the electric potential in the ionosphere for a given Φm. The MI coupling model is based on a Knight-type current-voltage relationship and a height-integrated conductivity model that depends on the energy deposited in the ionosphere by precipitating electrons. We show that the convergent electric field formed at the flanks of the BBF drive a FA potential drop and downward electron acceleration</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Ap%26SS.361..272A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016Ap%26SS.361..272A&link_type=ABSTRACT"><span id="translatedtitle">Juno's Earth flyby: the Jovian infrared <span class="hlt">Auroral</span> Mapper preliminary results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adriani, A.; Moriconi, M. L.; Mura, A.; Tosi, F.; Sindoni, G.; Noschese, R.; Cicchetti, A.; Filacchione, G.</p> <p>2016-08-01</p> <p>The Jovian InfraRed <span class="hlt">Auroral</span> Mapper, JIRAM, is an image-spectrometer onboard the NASA Juno spacecraft flying to Jupiter. The instrument has been designed to study the aurora and the atmosphere of the planet in the spectral range 2-5 μm. The very first scientific observation taken with the instrument was at the Moon just before Juno's Earth fly-by occurred on October 9, 2013. The purpose was to check the instrument regular operation modes and to optimize the instrumental performances. The testing <span class="hlt">activity</span> will be completed with pointing and a radiometric/spectral calibrations shortly after Jupiter Orbit Insertion. Then the reconstruction of some Moon infrared images, together with co-located spectra used to retrieve the lunar surface temperature, is a fundamental step in the instrument operation tuning. The main scope of this article is to serve as a reference to future users of the JIRAM datasets after public release with the NASA Planetary Data System.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6131723','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6131723"><span id="translatedtitle">A new model for <span class="hlt">auroral</span> breakup during substorms</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rothwell, P.L.; Block, L.P.; Falthammar, C.G.; Silevitch, M.B.</p> <p>1989-04-01</p> <p>A model for substorm breakup is developed, based on the relaxation of stretched (closed) dipolar field lines, and the formation of an incipient current wedge within a single arc structure. It is argued that the establishment of a coupled current structure within a single arc leads to a quasi-stable system; i.e., the pre-breakup regime. Perturbation of the pre-breakup structure leads to an instability criterion. It is found, consistent with observations, that narrower <span class="hlt">auroral</span> arcs at lower L shells undergo the most explosive poleward expansion. According to this model, the precise location at which breakup occurs depends on the O/sup +/ density in the plasma sheet, the level of magnetic <span class="hlt">activity</span> (K/sub p/), and the intensity of the substorm westward electrojet in the ionosphere. An enhancement of any of these features will cause breakup to occur at lower L shells. Comparison of our model with the Heppner-Maynard polar-cap potential model indicates that breakup is restricted to the west of the Harang discontinuity consistent with recent observations from the Viking satellite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=right+AND+Spanish&pg=4&id=EJ678825','ERIC'); return false;" href="http://eric.ed.gov/?q=right+AND+Spanish&pg=4&id=EJ678825"><span id="translatedtitle">Evaluating Teaching and <span class="hlt">Research</span> <span class="hlt">Activities</span>--Finding the Right Balance.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Vidal, Javier; Mora, Jose-Gines</p> <p>2003-01-01</p> <p>Analyzes on a national, regional, and institutional level the evaluation systems used to assess teaching and <span class="hlt">research</span> <span class="hlt">activities</span> at Spanish universities. Also examines ways in which evaluation systems orient to promote <span class="hlt">research</span> <span class="hlt">activities</span> to the detriment of teaching <span class="hlt">activities</span>. (SWM)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940030852','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940030852"><span id="translatedtitle">Analytic model of <span class="hlt">aurorally</span> coupled magnetospheric and ionospheric electrostatic potentials</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cornwall, J. M.</p> <p>1994-01-01</p> <p>This paper describes modest but significant improvements on earlier studies of electrostatic potential structure in the <span class="hlt">auroral</span> region using the adiabatic <span class="hlt">auroral</span> arc model. This model has crucial nonlinearities (connected, for example. with <span class="hlt">aurorally</span> produced ionization) which have hampered analysis; earlier work has either been linear, which I will show is a poor approximation or, if nonlinear, either numerical or too specialized to study parametric dependencies. With certain simplifying assumptions I find new analytic nonlinear solutions fully exhibiting the parametric dependence of potentials on magnetospheric (e.g.. cross-tail potential) and ionospheric (e.g., recombination rate) parameters. No purely phenomenological parameters are introduced. The results are in reasonable agreement with observed average <span class="hlt">auroral</span> potential drops, inverted-V scale sizes, and dissipation rates. The dissipation rate is quite comparable to tail energization and transport rates and should have a major effect on tail and magnetospheric dynamics. This paper gives various relations between the cross-tail potential and <span class="hlt">auroral</span> parameters (e.g., total parallel currents and potential drops) which can be studied with existing data sets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130003199','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130003199"><span id="translatedtitle">Space Weather Monitoring for ISS Space Environments Engineering and Crew <span class="hlt">Auroral</span> Observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Minow, Joseph; Pettit, Donald R.; Hartman, William A.</p> <p>2012-01-01</p> <p>Today s presentation describes how real time space weather data is used by the International Space Station (ISS) space environments team to obtain data on <span class="hlt">auroral</span> charging of the ISS vehicle and support ISS crew efforts to obtain <span class="hlt">auroral</span> images from orbit. Topics covered include: Floating Potential Measurement Unit (FPMU), . <span class="hlt">Auroral</span> charging of ISS, . Real ]time space weather monitoring resources, . Examples of ISS <span class="hlt">auroral</span> charging captured from space weather events, . ISS crew observations of aurora.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JASTP.146..129A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JASTP.146..129A&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Auroral</span> boundary movement rates during substorm onsets and their correspondence to solar wind and the AL index</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andriyas, Tushar</p> <p>2016-08-01</p> <p>A statistical analysis of the equatorward and poleward <span class="hlt">auroral</span> boundary movement during substorm onsets, the related solar wind <span class="hlt">activity</span>, GOES 8 and 10 magnetic field, and the westward <span class="hlt">auroral</span> electrojet (AL) index is undertaken, during the years 2000-2002. <span class="hlt">Auroral</span> boundary data were obtained from the British Antarctic Survey (BAS). These boundaries were derived using <span class="hlt">auroral</span> images from the IMAGE satellite. The timing of the onsets was derived from the Frey et al. (2004) database. Data were also classified based on the peak AL around the onset and the onset latitude, in order to analyze the differences, if any, in the rates of movement. It was found that the absolute ratio of the rate of movement of the mean poleward and equatorward boundaries was slower than the rate of mean movement around the midnight sector. The stronger the onset (in terms of the peak AL around the onset) was, the faster the rate of movement for both the boundaries. This implies that the stronger the AL signature around the onset, the weaker the magnetic field was prior to the onset and the faster it increased after the onset at GOES 8 and 10 locations. The stronger the AL signature, the thicker the latitudinal width of the aurora was, prior to the onset and higher was the increase in the width after the onset, due to large poleward and average equatorward expansion. Magnetotail field line stretching and relaxation rates as measured by GOES were also found to lie in the same order of magnitude. It is therefore concluded that the rates of latitudinal descent prior to a substorm onset and ascent after the onset, of the mean <span class="hlt">auroral</span> boundaries, corresponds to the rate at which the tail field lines stretch and relax before and after the onset, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED526917.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED526917.pdf"><span id="translatedtitle">Positive <span class="hlt">Activities</span>: Qualitative <span class="hlt">Research</span> with Parents. Solutions <span class="hlt">Research</span>. <span class="hlt">Research</span> Report. DCSF-RR142</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Department for Children, Schools and Families, 2009</p> <p>2009-01-01</p> <p>This <span class="hlt">research</span> was commissioned by COI and DCSF to understand in depth, the barriers, motivators and messages for parents to encourage participation in positive <span class="hlt">activities</span> for young people. Within this the <span class="hlt">research</span> was designed to understand the level of influence of parents in whether a young person participates/what a young person might…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880002885','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880002885"><span id="translatedtitle">An overview of Japanese CELSS <span class="hlt">research</span> <span class="hlt">activities</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nitta, Keiji</p> <p>1987-01-01</p> <p>Development of Controlled Ecological Life Support System (CELSS) technology is inevitable for future long duration stays of human beings in space, for lunar base construction and for manned Mars flight programs. CELSS functions can be divided into 2 categories, Environmental Control and Material Recycling. Temperature, humidity, total atmospheric pressure and partial pressure of oxygen and carbon dioxide, necessary for all living things, are to be controlled by the environment control function. This function can be performed by technologies already developed and used as the Environment Control Life Support System (ECLSS) of Space Shuttle and Space Station. As for material recycling, matured technologies have not yet been established for fully satisfying the specific metabolic requirements of each living thing including human beings. Therefore, <span class="hlt">research</span> <span class="hlt">activities</span> for establishing CELSS technology should be focused on material recycling technologies using biological systems such as plants and animals and physico-chemical systems, for example, a gas recycling system, a water purifying and recycling system and a waste management system. Japanese <span class="hlt">research</span> <span class="hlt">activities</span> were conducted and will be continued accordingly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SMaS...22j0301C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SMaS...22j0301C"><span id="translatedtitle">Electromechanically <span class="hlt">active</span> polymer transducers: <span class="hlt">research</span> in Europe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carpi, Federico; Graz, Ingrid; Jager, Edwin; Ladegaard Skov, Anne; Vidal, Frédéric</p> <p>2013-10-01</p> <p>Smart materials and structures based on electromechanically <span class="hlt">active</span> polymers (EAPs) represent a fast growing and stimulating field of <span class="hlt">research</span> and development. EAPs are materials capable of changing dimensions and/or shape in response to suitable electrical stimuli. They are commonly classified in two major families: ionic EAPs (<span class="hlt">activated</span> by an electrically induced transport of ions and/or solvent) and electronic EAPs (<span class="hlt">activated</span> by electrostatic forces). These polymers show interesting properties, such as sizable <span class="hlt">active</span> strains and/or stresses in response to electrical driving, high mechanical flexibility, low density, structural simplicity, ease of processing and scalability, no acoustic noise and, in most cases, low costs. Since many of these characteristics can also describe natural muscle tissues from an engineering standpoint, it is not surprising that EAP transducers are sometimes also referred to as 'muscle-like smart materials' or 'artificial muscles'. They are used not only to generate motion, but also to sense or harvest energy from it. In particular, EAP electromechanical transducers are studied for applications that can benefit from their 'biomimetic' characteristics, with possible usages from the micro- to the macro-scale, spanning several disciplines, such as mechatronics, robotics, automation, biotechnology and biomedical engineering, haptics, fluidics, optics and acoustics. Currently, the EAP field is just undergoing its initial transition from academic <span class="hlt">research</span> into commercialization, with companies starting to invest in this technology and the first products appearing on the market. This focus issue is intentionally aimed at gathering contributions from the most influential European groups working in the EAP field. In fact, today Europe hosts the broadest EAP community worldwide. The rapid expansion of the EAP field in Europe, where it historically has strong roots, has stimulated the creation of the 'European Scientific Network for Artificial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012epsc.conf..392A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012epsc.conf..392A"><span id="translatedtitle">EuroPlaNet VO use case: Giant planet HST <span class="hlt">auroral</span> emissions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>André, N.</p> <p>2012-09-01</p> <p>The field of planetary sciences has greatly expanded in recent years with space missions orbiting around most of the planets of our Solar System. The growing amount and wealth of data available make it difficult for scientists to exploit data coming from many sources that can initially be heterogeneous in their organization, description and format. It is an important objective of the Europlanet-RI and IMPEx projects (supported by EU within FP7) to add value to space missions by significantly contributing to the effective scientific exploitation of collected data; to enable space <span class="hlt">researchers</span> to take full advantage of the potential value of data sets. To this end and to enhance the science return from space missions, innovative tools have to be developed and offered to the community. AMDA (Automated Multi-Dataset Analysis, http://cdpp-amda.cesr.fr/) is a web-based facility developed at CDPP Toulouse in France (http://cdpp.cesr.fr) for on line analysis of space physics data (heliosphere, magnetospheres, planetary environments) coming from either its local database or distant ones. AMDA has been recently integrated as a service to the scientific community for the Plasma Physics thematic node of the Europlanet-RI IDIS (Integrated and Distributed Information Service, http://www.europlanet-idis.fi/) <span class="hlt">activities</span>, in close cooperation with IWF Graz (http://europlanetplasmanode. oeaw.ac.at/index.php?id=9). We will present our prototype Virtual Observatory <span class="hlt">activities</span> to connect the AMDA tool to the IVOA Aladin astrophysical tool to enable pluridisciplinary studies of giant planet <span class="hlt">auroral</span> emissions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890047624&hterms=electron+energy+distribution+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Delectron%2Benergy%2Bdistribution%2Bfunction','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890047624&hterms=electron+energy+distribution+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Delectron%2Benergy%2Bdistribution%2Bfunction"><span id="translatedtitle">Angular dependent transport of <span class="hlt">auroral</span> electrons in the upper atmosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lummerzheim, D.; Rees, M. H.; Anderson, H. R.</p> <p>1989-01-01</p> <p>The transport of <span class="hlt">auroral</span> electrons through the upper atmosphere is analyzed. The transport equation is solved using a discrete-ordinate method, including elastic and inelastic scattering of electrons (resulting in changes of pitch angle) and degradation in energy as the electrons penetrate into the atmosphere. The transport equation is solved numerically for the electron intensity as a function of altitude, pitch angle, and energy. In situ measurements of the pitch angle and energy distribution of precipitating electrons over an <span class="hlt">auroral</span> arc provide boundary conditions for the calculation. Model calculations were carried out with various different phase functions for elastic and inelastic collisions to attempt changing the angular scattering, but the observed pitch angle distributions remain unexplained. It is suggested that mechanisms other than collisional scattering influence the angular distribution of <span class="hlt">auroral</span> electrons at or below 300 km altitude in the low-energy domain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.5163R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.5163R"><span id="translatedtitle"><span class="hlt">Auroral</span> Kilometric Radiation and Type III Solar Radio Bursts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Romantsova, T. V.; Mogilevsky, M. M.; Skalsky, A. A.; Hanasz, J.</p> <p>2009-04-01</p> <p>Simultaneous wave observations onboard the ISEE-1 and ISEE-3 spacecraft show that onsets of the <span class="hlt">Auroral</span> Kilometric Radiation frequently coincide with an arrival of type III solar burst (Calvert, 1981). It was supposed that solar burst stimulates maser instability in <span class="hlt">auroral</span> region and AKR consequently . We present statistical and case studies of events when both type III solar radio bursts and <span class="hlt">Auroral</span> Kilometric Radiation are recorded simultaneously. AKR was observed onboard the INTERBALL-2 spacecraft orbiting around the Earth by the POLRAD experiment. Wave measurements carried out onboard the Wind, INTEBALL-TAIL and Geotail spacecraft are used to identify unambiguously the type III solar radio bursts. The origin of close relation between onsets of both solar radiation and AKR is discussed and interpreted. Acknowledgements. This work is supported by grant RFBR 06-02-72560.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6907757','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6907757"><span id="translatedtitle">Association of plasma sheet variations with <span class="hlt">auroral</span> changes during substorms</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hones, E.W. Jr.; Craven, J.D.; Frank, L.A.; Parks, G.K.</p> <p>1988-01-01</p> <p>Images of the southern <span class="hlt">auroral</span> oval taken by the University of Iowa <span class="hlt">auroral</span> imaging instrumentation on the Dynamics Explorer 1 satellite during an isolated substorm are correlated with plasma measurements made concurrently by the ISEE 1 satellite in the magnetotail. Qualitative magnetic field configuration changes necessary to relate the plasma sheet boundary location to the latitude of the auroras are discussed. Evidence is presented that the longitudinal advances of the auroras after expansive phase onset are mappings of a neutral line lengthening across the near-tail. We observe a rapid poleward <span class="hlt">auroral</span> surge, occurring about 1 hour after expansive phase onset, to coincide with the peak of the AL index and argue that the total set of observations at that time is consistent with the picture of a /open quotes/poleward leap/close quotes/ of the electrojet marking the beginning of the substorm's recovery. 9 refs. 3 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870041545&hterms=ohm+law&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dohm%2527s%2Blaw','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870041545&hterms=ohm+law&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dohm%2527s%2Blaw"><span id="translatedtitle">The current-voltage relationship in <span class="hlt">auroral</span> current sheets</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weimer, D. R.; Gurnett, D. A.; Goertz, C. K.; Menietti, J. D.; Burch, J. L.</p> <p>1987-01-01</p> <p>The current-voltage relation within narrow <span class="hlt">auroral</span> current sheets is examined through the use of high-resolution data from the high altitude Dynamics Explorer 1 satellite. The north-south perpendicular electric field and the east-west magnetic field are shown for three cases in which there are large amplitude, oppositely directed paired electric fields and narrow current sheets. These data are shown to indicate that there is a linear Ohm's law relationship between the current density and the parallel potential drop within the narrow current sheets. This linear relationship had previously been verified for large-scale <span class="hlt">auroral</span> formations greater than 20 km wide at the ionosphere. The evidence shown here extends our knowledge down to the scale size of discrete <span class="hlt">auroral</span> arcs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810016112','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810016112"><span id="translatedtitle">Effects of turbulence on a kinetic <span class="hlt">auroral</span> arc model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cornwall, J. M.; Chiu, Y. T.</p> <p>1981-01-01</p> <p>A plasma kinetic model of an inverted-V <span class="hlt">auroral</span> arc structure which includes the effects of electrostatic turbulence is proposed. In the absence of turbulence, a parallel potential drop is supported by magnetic mirror forces and charge quasi neutrality, with energetic <span class="hlt">auroral</span> ions penetrating to low altitudes; relative to the electrons, the ions' pitch angle distribution is skewed toward smaller pitch angles. The electrons energized by the potential drop form a current which excites electrostatic turbulence. In equilibrium the plasma is marginally stable. The conventional anomalous resistivity contribution to the potential drop is very small. Anomalous resistivity processes are far too dissipative to be powered by <span class="hlt">auroral</span> particles. It is concluded that under certain circumstances equilibrium may be impossible and relaxation oscillations set in.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19730045166&hterms=Twins+identical+twins&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DTwins%2Bidentical%2Btwins','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19730045166&hterms=Twins+identical+twins&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DTwins%2Bidentical%2Btwins"><span id="translatedtitle">Twin payload observations of incident and backscattered <span class="hlt">auroral</span> electrons.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reasoner, D. L.; Chappell, C. R.</p> <p>1973-01-01</p> <p>Energy spectra and pitch angle distributions of <span class="hlt">auroral</span> electrons have been measured in a premidnight multiple arc <span class="hlt">auroral</span> display by a Javelin rocket containing two identical payloads that separated in flight. The rocket was launched from Fort Churchill, Canada, at 0459 UT on March 2, 1968, and covered an altitude range up to 800 km. The electron energy spectra between 40 eV and 20 keV show a 'continuum' spectrum with a superimposed energetic peak. The center energy of the peak was observed to shift from 10-12 keV over the arcs to 2-3 keV between the arcs. This spectral structure is shown to be similar to the inverted 'V' structure reported by other investigators. The in flight separation of the two payloads allowed investigation of spatial versus temporal effects in the <span class="hlt">auroral</span> precipitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19740042010&hterms=ISIS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DISIS','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19740042010&hterms=ISIS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DISIS"><span id="translatedtitle">Polar cap <span class="hlt">auroral</span> electron fluxes observed with Isis 1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Winningham, J. D.; Heikkila, W. J.</p> <p>1974-01-01</p> <p>Three types of <span class="hlt">auroral</span> particle precipitation have been observed over the polar caps, well inside the <span class="hlt">auroral</span> oval, by means of the soft particle spectrometer on the Isis 1 satellite. The first type is a uniform, very soft (about 100 eV) electron 'polar rain' over the entire polar cap; this may well be present with very weak intensity at all times, but it is markedly enhanced during worldwide geomagnetic storms. A second type of precipitation is a structured flux of electrons with energies near 1 keV, suggestive of localized 'polar showers'; it seems likely that these are the cause of the sun-aligned <span class="hlt">auroral</span> arcs that have been observed during moderately quiet conditions. During periods of intense magnetic disturbance this precipitation can become very intense and exhibit a characteristic pattern that we have come to call a 'polar squall'.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSA44A..08C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSA44A..08C"><span id="translatedtitle">Accelerated <span class="hlt">Auroral</span> Zone Ions: Results from the VISIONS Mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clemmons, J. H.; Lemon, C. L.; Hecht, J. H.; Rowland, D. E.; Pfaff, R. F.; Klenzing, J.</p> <p>2013-12-01</p> <p>Presented are results from the VISIONS <span class="hlt">auroral</span> sounding rocket mission. The presentation focuses on the measured fluxes of locally-accelerated ions and the accompanying measurements of electron fluxes, electric and magnetic DC and wave fields, and <span class="hlt">auroral</span> emissions. The accelerated ions are shown to have their highest energies and most intense fluxes near the poleward <span class="hlt">auroral</span> boundary, and are present at all down-going pitch angles. They are also proximate to intense fluxes of field-aligned electrons and strong waves, and appear in conjunction with the intensification of an isotropic population of much more energetic ion precipitation. The measurements are interpreted in the context of the 'pressure cooker' mechanism used to explain similar observations, and the implications of this interpretation for the ion outflow process in this event are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5246146','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5246146"><span id="translatedtitle">A transient <span class="hlt">auroral</span> event on the dayside</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Heikkila, W.J. ); Jorgensen, T.S. ); Lanzerotti, L.J.; Maclennan, C.G. )</p> <p>1989-10-01</p> <p>On December 5, 1986, high-latitude magnetometer stations in Greenland, as well as Iqaluit and the South Pole, showed a strong perturbation lasting for about 10 min beginning at 0930 UT in an otherwise quiet period. A pair of field aligned currents separated in the east-west sense and moving westward (tailward) at 4--5 km/s is consistent with the data, producing a twin vortex pattern of Hall currents. Similar perturbations, but with reduced intensity, were also recorded on the afternoon side of Svalbard, Heiss Island, and several locations in northern Siberia. The perturbation was also observed with the incoherent scatter radar at Sondrestrom, these data agreeing with the twin vortex pattern. The perturbation was accompanied by <span class="hlt">auroral</span> forms overhead at Sondrestrom that also traveled westward. Meridian scanning photometer recordings at the radar site showed the cleft, located about 3{degree} to 5{degree} poleward in latitude; the cleft did not move from the far northern sky for several hours, even while the disturbance was observed. Viking and Polar Bear satellites passed just before the disturbance over Greenland and DMSP encountered the disturbance near Baffin Island a few minutes later; these spacecraft observations increased our confidence in the interpretation of the data. ISEE 1/2 and IMP 8 recorded a magnetic disturbance in the solar wind, the likely cause of this event. Similar observations by others have been associated with flux transfer events. However, since the observed event occurred on closed field lines, our interpretation is quite different; it is that an impulsive penetration of solar wind plasma on an interplanetary magnetic flux tube took place through the magnetopause, ending up in the low latitude boundary layer. Some efficient mechanism is required to feed the boundary layer with the total amount observed. Other events reported in the literature may have a similar explanation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6904297','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6904297"><span id="translatedtitle">A transient <span class="hlt">auroral</span> event on the dayside</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Heikkila, W.J. ); Jorgensen, T.S. ); Lanzerotti, L.J.; Maclennan, C.G. )</p> <p>1989-11-01</p> <p>On December 5, 1986, high-latitude magnetometer stations in Greenland, as well as Iqaluit and the South Pole, showed a strong perturbation lasting for about 10 min beginning at 0930 UT in an otherwise quiet period. A pair of field aligned currents separated in the east-west sense and moving westward (tailward) at 4--5 km/s is consistent with the data, producing a twin vortex pattern of Hall currents. Similar perturbations, but with reduced intensity, were also recorded on the afternoon side at Svalbard, Heiss Island, and several locations in northern Siberia. The perturbation was also observed with the incoherent scatter radar at Sondrestrom, these data agreeing with the twin vortex pattern. The perturbation was accompanied by <span class="hlt">auroral</span> forms overhead at Sondrestrom that also traveled westward. Meridian scanning photometer recordings at the radar site showed the cleft, located about 3{degree} to 5{degree} poleward in latitude; the cleft did not move from the far northern sky for several hours, even while the disturbance was observed. Viking and Polar Bear satellites passed just before the disturbance over Greenland and DMSP encountered the disturbance near Baffin Island a few minutes later; these spacecraft observations increased our confidence in the interpretation of the data. ISEE 1/2 and IMP 8 recorded a magnetic disturbance in the solar wind, the likely cause of this event. Similar observations by others have been associated with flux transfer events. However, since the observed event occurred on closed field lines, our interpretation is quite different; it is that an impulsive penetration of solar wind plasma on an interplanetary magnetic flux tube took place through the magnetopause, ending up in the low latitude boundary layer. Some efficient mechanism is required to feed the boundary layer with the total amount observed. Other events reported in the literature may have a similar explanation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/121260','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/121260"><span id="translatedtitle">Electrodynamic parameters in the nighttime sector during <span class="hlt">auroral</span> substorms</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fujii, R.; Hoffman, A.; Anderson, P.C.</p> <p>1994-04-01</p> <p>The characteristics of the large-scale electrodynamic parameters, field-aligned currents (FACs), electric fields, and electron precipitation, which are associated with <span class="hlt">auroral</span> substorm events in the nighttime sector, have been obtained through a unique analysis which places the ionospheric measurements of these parameters into the context of a generic substorm determined from global <span class="hlt">auroral</span> images. A generic bulge-type <span class="hlt">auroral</span> emission region has been deduced from <span class="hlt">auroral</span> images taken by the Dynamics Explorer 1 (DE 1) satellite during a number of isolated substorms, and the form has been divided into six sectors, based on the peculiar emission characteristics in each vector: west of bulge, surge horn, surge, middle surge, eastern bulge, and east of bulge. By comparing the location of passes of the Dynamics Explorer 2 (DE 2) satellite to the simultaneously obtained <span class="hlt">auroral</span> images, each pass is placed onto the generic aurora. The organization of DE 2 data in this way has systematically clarified peculiar characteristics in the electrodynamic parameters. An upward net current mainly appears in the surge, with little net current in the surge horn and the west of bulge. Near the poleward boundary of the expanding <span class="hlt">auroral</span> bulge, a pair of oppositely directed FAC sheets is observed, with the downward FAC on the poleward side. This downward FAC and most of the upward FAC in the surge and the middle surge are associated with narrow, intense antisunward convection, corresponding to an equatorward directed spikelike electric field. This pair of currents decreases in amplitude and latitudinal width toward dusk in the surge and the west of bulge, and the region 1 and 2 FACs become embedded in the sunward convection region. The upward FAC region associated with the spikelike field on the poleward edge of the bulge coincides well with intense electron precipitation and aurora appearing in this western and poleward portion of the bulge. 44 refs., 14 figs., 2 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20080037609&hterms=Michel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DMichel','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20080037609&hterms=Michel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DMichel"><span id="translatedtitle">Saturn's <span class="hlt">Auroral</span> Response to the Solar Wind: Centrifugal Instability Model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sittler, Edward C.; Blanc, Michel F.; Richardson, J. D.</p> <p>2008-01-01</p> <p>We describe a model initially presented by Sittler et al. [2006] which attempts to explain the global response of Saturn's magnetosphere and its corresponding <span class="hlt">auroral</span> behavior to variations in the solar wind. The model was derived from published simultaneous Hubble Space Telescope (HST) <span class="hlt">auroral</span> images and Cassini upstream measurements taken during the month of January 2004. These observations show a direct correlation between solar wind dynamic pressure and (1) <span class="hlt">auroral</span> brightening toward dawn local time, (2) an increase of rotational movement of <span class="hlt">auroral</span> features to as much as 75% of the corotation speed, (3) the movement of the <span class="hlt">auroral</span> oval to higher latitudes and (4) an increase in the intensity of Saturn Kilometric Radiation (SKR). This model is an alternative to the reconnection model of Cowley et al. [2004a,b; 2005] which is more Earth-like while ours stresses rotation. If angular momentum is conserved in a global sense, then when compressed the magnetosphere will tend to spin up and when it expands will tend to spin down. With the plasma sheet outer boundary at L approximates 15 we argue this region to be the dominant source region for the precipitating particles. If radial transport is dominated by centrifugal driven flux tube interchange motions, then when the magnetosphere spins up, outward transport will increase, the precipitating particles will move radially outward and cause the <span class="hlt">auroral</span> oval to move to higher latitudes as observed. The Kelvin-Helmholtz instability may contribute to the enhanced emission along the dawn meridian as observed by HST. We present this model in the context of presently published observations by Cassini.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890041550&hterms=electron+energy+distribution+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Delectron%2Benergy%2Bdistribution%2Bfunction','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890041550&hterms=electron+energy+distribution+function&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Delectron%2Benergy%2Bdistribution%2Bfunction"><span id="translatedtitle">Excitation of low-frequency waves by <span class="hlt">auroral</span> electron beams</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lin, C. S.; Wong, H. K.; Koga, J.; Burch, J. L.</p> <p>1989-01-01</p> <p>The electron distribution functions measured by the Dynamics Explorer 1 satellite during an <span class="hlt">auroral</span> pass in 1981 are used in a linear instability analysis of low-frequency electromagnetic and electrostatic waves near and below the hydrogen gyrofrequency. It is suggested that the low-frequency electric and magnetic noise in the <span class="hlt">auroral</span> zone might be explained by O and H electromagnetic ion cyclotron waves excited by energetic electron beams. An instability analysis suggests that upward and downward streaming electrons throughout the central plasma sheet region provide the free energy for heating oxygen ion through oxygen electrostatic ion cyclotron waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870039720&hterms=electrodynamics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Delectrodynamics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870039720&hterms=electrodynamics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Delectrodynamics"><span id="translatedtitle">Feedback between neutral winds and <span class="hlt">auroral</span> arc electrodynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lyons, L. R.; Walterscheid, R. L.</p> <p>1986-01-01</p> <p>The feedback between neutral atmospheric winds and the electrodynamics of a stable, discrete <span class="hlt">auroral</span> arc is analyzed. The ionospheric current continuity equation and the equation for neutral gas acceleration by ion drag are solved simultaneously, as a function of time. The results show that, in general, the electric field in the ionosphere adjusts to neutral wind acceleration so as to keep <span class="hlt">auroral</span> field-aligned currents and electron acceleration approximately independent of time. It is thus concluded that the neutral winds that develop as a result of the electrodynamical forcing associated with an arc do not significantly affect the intensity of the arc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760013660','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760013660"><span id="translatedtitle">The earth as a radio source. [noting <span class="hlt">auroral</span> kilometric radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gurnett, D. A.</p> <p>1975-01-01</p> <p>The primary characteristics of radio emission from the earth's magnetosphere are summarized, the origins of these missions are considered and similarities to other astronomical radio sources discussed. The <span class="hlt">auroral</span> kilometric radiation has features very similar to Io-related decametric radiation from Jupiter and from Saturn. The radiation at fp and 2 fp upstream of the bow shock appears to be generated by the same mechanism as type III solar radio bursts. The beaming of the <span class="hlt">auroral</span> kilometric radiation into a cone shaped region over the polar cap has some similarity to the angular distribution of radiation from Io and to the beaming of radio emission from pulsars.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25375713','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25375713"><span id="translatedtitle">Backward wave cyclotron-maser emission in the <span class="hlt">auroral</span> magnetosphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Speirs, D C; Bingham, R; Cairns, R A; Vorgul, I; Kellett, B J; Phelps, A D R; Ronald, K</p> <p>2014-10-10</p> <p>In this Letter, we present theory and particle-in-cell simulations describing cyclotron radio emission from Earth's <span class="hlt">auroral</span> region and similar phenomena in other astrophysical environments. In particular, we find that the radiation, generated by a down-going electron horseshoe distribution is due to a backward-wave cyclotron-maser emission process. The backward wave nature of the radiation contributes to upward refraction of the radiation that is also enhanced by a density inhomogeneity. We also show that the radiation is preferentially amplified along the <span class="hlt">auroral</span> oval rather than transversely. The results are in agreement with recent Cluster observations. PMID:25375713</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvL.113o5002S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvL.113o5002S"><span id="translatedtitle">Backward Wave Cyclotron-Maser Emission in the <span class="hlt">Auroral</span> Magnetosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Speirs, D. C.; Bingham, R.; Cairns, R. A.; Vorgul, I.; Kellett, B. J.; Phelps, A. D. R.; Ronald, K.</p> <p>2014-10-01</p> <p>In this Letter, we present theory and particle-in-cell simulations describing cyclotron radio emission from Earth's <span class="hlt">auroral</span> region and similar phenomena in other astrophysical environments. In particular, we find that the radiation, generated by a down-going electron horseshoe distribution is due to a backward-wave cyclotron-maser emission process. The backward wave nature of the radiation contributes to upward refraction of the radiation that is also enhanced by a density inhomogeneity. We also show that the radiation is preferentially amplified along the <span class="hlt">auroral</span> oval rather than transversely. The results are in agreement with recent Cluster observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980137588','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980137588"><span id="translatedtitle">Spatial Relationships of <span class="hlt">Auroral</span> Particle Acceleration Relative to High Latitude Plasma Boundaries</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ghielmetti, Arthur G.</p> <p>1997-01-01</p> <p>This final report describes the <span class="hlt">activities</span> under NASA contract to Lockheed Missiles and Space Company. It covers the period from 10-1-94 to 12-31-97. The objective of this investigation is to identify and characterize the spatial relationships of <span class="hlt">auroral</span> particle acceleration features relative to the characteristic transition features in the surrounding polar ionospheric plasmas. Due to the reduced funding level approved for this contract, the original scope of the proposed work was readjusted with the focus placed on examining spatial relationships with respect to particle structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890036918&hterms=Barium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBarium','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890036918&hterms=Barium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBarium"><span id="translatedtitle">Search for <span class="hlt">auroral</span> belt E-parallel fields with high-velocity barium ion injections</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Heppner, J. P.; Ledley, B. G.; Miller, M. L.; Marionni, P. A.; Pongratz, M. B.</p> <p>1989-01-01</p> <p>In April 1984, four high-velocity shaped-charge Ba(+) injections were conducted from two sounding rockets at 770-975 km over northern Alaska under conditions of <span class="hlt">active</span> <span class="hlt">auroral</span> and magnetic disturbance. Spatial ionization (brightness) profiles of high-velocity Ba(+) clouds from photometric scans following each release were found to be consistent with the 28-sec theoretical time constant for Ba photoionization determined by Carlsten (1975). These observations therefore revealed no evidence of anomalous fast ionization predicted by the Alfven critical velocity hypothesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/207165','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/207165"><span id="translatedtitle">A comparison of Viking UVI <span class="hlt">auroral</span> observations and model calculations of camera responses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Steele, D.P.; McEwen, D.J.; Murphree, J.S.</p> <p>1995-03-01</p> <p>The authors have selected a number of events observed by the UV imager on Viking both in the UV Lyman, Birge, Hopfield wavelength, and the O I 130.4 nm and 135.6 nm bands, where there was simultaneous DMSP F7 particle data for comparision. These events were selected from times of quiet to moderately <span class="hlt">active</span> ionospheric conditions with stable electron precipitation around the region of observation. They have then done model calculations of <span class="hlt">auroral</span> emissions, corresponding radiative transfer, and folded in the response functions for the UV cameras. They achieved good comparisons with 5 of the 6 events which were modeled.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2204960G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2204960G"><span id="translatedtitle">IAU Project and <span class="hlt">Research</span> <span class="hlt">Activity</span> in Nepal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gautam, Suman</p> <p>2015-08-01</p> <p>The second half of the twentieth century has witnessed a tremendous development in the field of astronomy and space exploration. The large telescope both on the land and in the orbit, using the whole range of the electromagnetic spectra from radio waves to gamma rays are extending their range of exploration, right to the edge of the observable universe, and making astounding discoveries in the process. Many large international telescope facilities and global plans are accessible to all astronomers throughout the world, providing an inexpensive entry to cutting- edge international <span class="hlt">research</span> for developing countries.Nepal is a mountainous country it has a wide range of climatic and altitude variations which varies from an elevation of 200 meter to ≥ 4000 meter. The average temperature varies from ≥ 25 o C to ≤ 0 to 5oC. Because of these diverse weather and climatic variation there is the potential for the establishment of sophisticated observatory/ data centre and link with each other. So, the future possible opportunity of astronomy in Nepal will be discussed. Besides Education and <span class="hlt">Research</span> <span class="hlt">activities</span> conducted in Tribhuvan University, Nepal under the support of International Astronomical Union (IAU) will also be highlighted. The importance brought by those two workshops conducted on data simulation supported by IAU under TF1 will also be discussed which is believed to play a vital role for the promotion and development of astronomy and astrophysics in developing countries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSA42A..07C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSA42A..07C"><span id="translatedtitle">Fine Scale Structure observed in the Total Electron Content above the Sub-<span class="hlt">Auroral</span>, <span class="hlt">Auroral</span>, and Polar Ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Coster, A. J.; Thomas, E. G.; Vierinen, J.; Rideout, W. E.</p> <p>2015-12-01</p> <p>This paper details recent improvements in TEC observations made in the sub-<span class="hlt">auroral</span>, <span class="hlt">auroral</span>, and polar regions. The goal is high-resolution measurements of both medium and fine-scale TEC-gradients. To achieve this, the number of GNSS receivers processed was more than doubled, due to agreements made with multiple government and commercial agencies, such as those involved with highway transportation and precision farming. Following the increase in GNSS observations, additional improvements were made in the MIT Haystack GNSS data processing algorithms, allowing for finer grid spacing of the output TEC data. Merging data sets also increased sensitivity. Scintillation data from several GNSS receivers have been overlaid on top of all-sky camera images showing evidence of aurora. These data sets have been merged with the measured background TEC to monitor the development both medium and fine-scale TEC gradients. Data from multiple geomagnetic storms and <span class="hlt">auroral</span> events in this solar cycle will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT........22Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT........22Z"><span id="translatedtitle">Model-based optical and radar remote sensing of transport and composition in the <span class="hlt">auroral</span> ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zettergren, Matthew David</p> <p></p> <p>The terrestrial ionosphere is heavily influenced by electrodynamic and inertial coupling with the magnetosphere. This coupling is most apparent at high latitudes where precipitating electrons and electromagnetic disturbances associated with auroras greatly alter temperatures and motions of the ionospheric plasma. Among other effects, <span class="hlt">auroral</span> electrons are responsible for heating ionospheric electrons and producing ion upflows. Perpendicular electric fields frictionally heat ionospheric ions, resulting in drastic modifications to chemical reaction rates which control F-region ion composition. The lasting effects of upflows and composition on the magnetosphere-ionosphere system are poorly understood due to a sparsity of measurements of these processes. This shortage of measurements is addressed by developing two new remote sensing techniques: one for estimating ion upflows from optical measurements and another for estimating ion composition from incoherent scatter radar (ISR) data. This <span class="hlt">research</span> develops an underutilized diagnostic for ion upflows: <span class="hlt">auroral</span> optical emissions. Systematic theoretical modeling efforts demonstrate that emission features with wavelengths of 630.0 nm, 732-733 nm, and 844.6 nm are ideal indicators of upflow. A technique is then developed which uses multi-spectral <span class="hlt">auroral</span> optical measurements to estimate ion upflow. This technique is applied in two steps: (1) multi-spectral optical data are inverted, using a physics-based kinetic model of electron energy deposition, to estimate electron precipitation; (2) this precipitation is used as input to a ionospheric model to calculate the resulting ion upflow. This technique is applied to near-infrared (700-850 nm wavelength) optical observations from an event occurring on 17 February 2001 at the Sondrestrom <span class="hlt">research</span> facility. Estimated ion upflow is shown to be accurate through quantitative comparisons with concurrent ISR observations. A method for estimating ion composition from ISR data is also</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850034471&hterms=left-handed&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dleft-handed','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850034471&hterms=left-handed&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dleft-handed"><span id="translatedtitle">The plasma wave environment of an <span class="hlt">auroral</span> arc. II - ULF waves on an <span class="hlt">auroral</span> arc boundary</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gelpi, C. G.; Bering, E. A.</p> <p>1984-01-01</p> <p>On March 9, 1978, a sounding rocket launched from Poker Flat, Alaska, at 2200 LT, made a four-component measurement of a 0.5 Hz hydromagnetic wave as the payload crossed the poleward boundary of a quiet homogeneous <span class="hlt">auroral</span> arc. An energy flux of about 10 to the -6th W/sq m was observed propagating upward with a left-handed polarization within the arc, and a flux 6 times greater was observed propagating downward with a right-handed polarization on the arc boundary. The waves were identified as shear mode Alfven waves. Various models for the source of the free energy are discussed with the conclusion that the most likely production mechanism was either the electromagnetic or electrostatic Kelvin-Helmholtz instability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JGRA..116.2304A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JGRA..116.2304A"><span id="translatedtitle">A statistical investigation of the Cowling channel efficiency in the <span class="hlt">auroral</span> zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amm, O.; Fujii, R.; Kauristie, K.; Aikio, A.; Yoshikawa, A.; Ieda, A.; Vanhamäki, H.</p> <p>2011-02-01</p> <p>The Cowling channel mechanism describes the creation of a secondary polarization electric field at sharp conductance boundaries in the ionosphere due to excess charges for the case in which the release of these charges to the magnetosphere is fully or partially impeded. The secondary currents generated by the polarization electric field effectively modify the effective ionospheric conductivity inside the Cowling channel. While the Cowling mechanism is generally accepted for the equatorial electrojet, there is a long-standing discussion about the importance of this mechanism and its efficiency in the <span class="hlt">auroral</span> electrojet. We present a statistical investigation that enables us to identify the most probable geospace conditions and MLT locations for a high Cowling efficiency. This investigation is based on more than 1600 meridional profiles of data from the Magnetometers-Ionospheric Radars-All-sky Cameras Large Experiment (MIRACLE) network in Scandinavia, in particular, ground magnetic field data from the International Monitor for <span class="hlt">Auroral</span> Geomagnetic Effects (IMAGE) magnetometer network and electric field data from the Scandinavian Twin <span class="hlt">Auroral</span> Radar Experiment (STARE) radar, supported with pointwise ionospheric conductance measurements from the European Incoherent Scatter (EISCAT) radar. We analyze the data in the framework of a 3-D ionospheric model, but our data set is filtered so that only electrojet-type situations are included so that the gradients of all measured quantities in longitudinal direction can be neglected. The analysis results in a steep peak of high Cowling channel efficiency probability in the early morning sector (0245-0645 MLT), with the largest probability around 0500 MLT and for medium and high geomagnetic <span class="hlt">activity</span>. In agreement with an earlier single-event study by Amm and Fujii (2008), this indicates that the Cowling mechanism may be most effective in the early morning part of the central substorm bulge. Further, our analysis results in an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JGRA..114.9302B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JGRA..114.9302B"><span id="translatedtitle">Experimental tests of the generation mechanism of <span class="hlt">auroral</span> medium frequency burst radio emissions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bunch, N. L.; Labelle, J.; Weatherwax, A. T.; Hughes, J. M.; Lummerzheim, D.</p> <p>2009-09-01</p> <p>Medium frequency (MF) burst is an impulsive <span class="hlt">auroral</span> radio emission at 1.3-4.5 MHz commonly detected by ground-based instruments for a few minutes at substorm onsets. It is thought to arise from mode conversion radiation. The Dartmouth College MF radio interferometer at Toolik Field Station, Alaska (68.51° invariant latitude), measured spectra, amplitudes, and directions of arrival (DOA) of 47 MF burst events during 2006-2007 and 49 events during 2007-2008. Statistical analysis of these events shows that they come predominantly from the south and east of Toolik, as expected because propagation conditions are more favorable poleward and westward of the <span class="hlt">active</span> <span class="hlt">auroral</span> arcs than equatorward or eastward during premidnight (westward moving) substorm onset <span class="hlt">activity</span>. Case studies of a selected MF burst event on 20 November 2007 show that motions of the radio emissions qualitatively track the motions of <span class="hlt">auroral</span> arcs simultaneously observed with all-sky camera. Case studies of DOA data of selected MF burst events on 31 January and 20 November 2007 show that higher-frequency components of MF burst arrive at higher elevation angles than lower-frequency components. Statistical studies confirm this trend. Ray-tracing analysis shows that this trend implies that sources of the higher-frequency components of the MF burst are at higher altitudes than those of the lower-frequency components. The analysis also shows that the MF burst comes from the bottomside F region ionosphere. These observations are consistent with a mechanism of MF burst emission whereby the emissions originate from mode conversion of Langmuir or upper hybrid waves excited over a range of altitudes in the bottomside F region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSM43B2239N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSM43B2239N"><span id="translatedtitle">Chorus Wave Scattering Responsible for the Dayside Diffuse <span class="hlt">Auroral</span> Precipitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ni, B.; Nishimura, T.; Bortnik, J.; Thorne, R. M.; Li, W.; Angelopoulos, V.; Ebihara, Y.; Weatherwax, A. T.</p> <p>2012-12-01</p> <p>We perform a comprehensive theoretical and numerical analysis on the conjunction measurements of dayside diffuse aurora and whistler-mode chorus waves by the South Pole all-sky imager and THEMIS spacecraft at 16 -18 UT on August 13, 2009. A high correlation is identified between the intensities of the diffuse aurora at 557.7 nm near the THEMIS ionospheric footprints and chorus emissions. Using the simultaneous wave, plasma density and particle datasets of THEMIS observations, we compute the matrices of bounce-averaged diffusion coefficients due to chorus wave scattering in the realistic magnetosphere at a series of representative time stamps, which are subsequently utilized to quantitatively compare with the rate of strong diffusion for evaluating the energy dependent loss cone filling index associated with chorus-induced pitch angle scattering. Fits of Maxwellian-type energy spectrum to the modeled electron differential fluxes inside the loss cone produce a temporal variation of the total energy flux and characteristic energy of precipitating electrons. The obtained dominant precipitation energies are within 2 - 5 keV, which agrees well with the major electron population for the dayside green-line aurora excitation. The modeled change of the total precipitation energy flux is remarkably consistent with that of the observed green-line diffuse aurora intensity. The trend of decreases and increases in the aurora luminosity is also reasonably reproduced in a time consistent manner. Through a systematic combination of quasi-linear theory, realistic non-dipolar magnetic field mapping, and the concept of strong diffusion on the basis of conjugated space and ground observations, we have demonstrated that dayside chorus scattering can dominantly account for the dayside green-line diffuse aurora <span class="hlt">activity</span>, while variations in electron differential flux also play a role. In addition, changes in the ambient density can affect the portion of diffuse <span class="hlt">auroral</span> electrons that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=recruitment+AND+staff&pg=6&id=EJ567075','ERIC'); return false;" href="http://eric.ed.gov/?q=recruitment+AND+staff&pg=6&id=EJ567075"><span id="translatedtitle">Nursing <span class="hlt">Research</span>--Taking an <span class="hlt">Active</span> Interest.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Cleverly, Dankay</p> <p>1998-01-01</p> <p>In Britain, nurses' attitudes toward <span class="hlt">research</span> are changing. Schools of nursing must consider the following <span class="hlt">research</span> issues: funding, contracts, support, publication, and staff recruitment and retention. (SK)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=307546&keyword=Cooking&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77952671&CFTOKEN=51953307','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=307546&keyword=Cooking&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=77952671&CFTOKEN=51953307"><span id="translatedtitle">Update on U.S.EPA Cookstove <span class="hlt">Research</span> <span class="hlt">Activities</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The presentation includes background information on EPA's stove <span class="hlt">research</span>, focuses on cookstove testing for air pollutant emissions and energy efficiency, and briefly describes current <span class="hlt">research</span> <span class="hlt">activities</span>. Ongoing <span class="hlt">activities</span> are highlighted, and EPA contacts are provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110023300','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110023300"><span id="translatedtitle">A Rocket-Base Study of <span class="hlt">Auroral</span> Electrodynamics Within the Current Closure Ionosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kaeppler, Stephen R.; Kletzing, Craig; Bounds, Scott R.; Sigsbee, Kristine M.; Gjerloev, Jesper W.; Anderson, Brian Jay; Korth, Haje; Lessard, Marc; Labelle, James W.; Dombrowski, Micah P.; Pfaff, Robert F.; Rowland, Douglas E.; Jones, Sarah; Heinselman, Craig J.; DudokdeWit, Thierry</p> <p>2011-01-01</p> <p>The <span class="hlt">Auroral</span> Current and Electrodynamics Structure (ACES) mission consisted of two sounding rockets launched nearly simultaneously from Poker Flat <span class="hlt">Research</span> Range, AK on January 29, 2009 into a dynamic multiple-arc aurora. The ACES rocket mission, in conjunction with the PFISR Radar, was designed to observe the three-dimensional current system of a stable <span class="hlt">auroral</span> arc system. ACES utilized two well instrumented payloads flown along very similar magnetic field footprints, at various altitudes with small temporal separation between both payloads. ACES High, the higher altitude payload (apogee 360 km), took in-situ measurements of the plasma parameters above the current closure region to provide the input signature into the lower ionosphere. ACES Low, the low-altitude payload (apogee 130 km), took similar observations within the current closure region, where cross-field currents can flow. We present results comparing observations of the electric fields, magnetic fields, electron flux, and the electron temperature at similar magnetic footpoints between both payloads. We further present data from all-sky imagers and PFISR detailing the evolution of the <span class="hlt">auroral</span> event as the payloads traversed regions connected by similar magnetic footpoints. Current measurements derived from the magnetometers on both payloads are further compared. We examine data from both PFISR and observations on the high-altitude payload which we interpreted as a signature of electron acceleration by means of Alfv n waves. We further examine all measurements to understand ionospheric conductivity and how energy is being deposited into the ionosphere through Joule heating. Data from ACES is compared against models of Joule heating to make inferences regarding the effect of collisions at various altitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920006286','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920006286"><span id="translatedtitle">Generation of field-aligned current in the <span class="hlt">auroral</span> zone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Okuda, Hideo</p> <p>1991-01-01</p> <p>Generation of a magnetic field-aligned current in the <span class="hlt">auroral</span> zone connecting the magnetospheric and ionospheric plasmas has been studied by means of a three dimensional particle simulation model. The model is of a magnetostatic variety appropriate for a low beta plasma in which the high frequency transverse displacement current has been eliminated. The simulation model is highly elongated along the magnetic field lines in order to model a highly elongated flux tube in the <span class="hlt">auroral</span> zone. An enhanced field-aligned current was generated by injection of a magnetospheric plasma across the <span class="hlt">auroral</span> zone magnetic field at the center of the model. Such a plasma injection may correspond to a plasmoid injection at the geomagnetic tail associated with magnetic reconnection during a substorm or a transverse plasma flow along the low latitude magnetopause boundary layer. The results of the simulations show that the field-aligned current can be enhanced over the thermal current by a factor of 5 - 10 via such injection. Associated with the enhanced current are the electrostatic ion cyclotron waves and shear Alfven waves excited in the <span class="hlt">auroral</span> zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AnGeo..29..701A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AnGeo..29..701A"><span id="translatedtitle">Observations of an <span class="hlt">auroral</span> streamer in a double oval configuration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amm, O.; Nakamura, R.; Takada, T.; Kauristie, K.; Frey, H. U.; Owen, C. J.; Aikio, A.; Kuula, R.</p> <p>2011-04-01</p> <p>During the late evening and night of 14 September 2004, the nightside <span class="hlt">auroral</span> oval shows a distinct double oval configuration for several hours after a substorm onset at ~18:45 UT. This structure is observed both by the IMAGE satellite optical instruments focusing on the Southern Hemisphere, and by the MIRACLE ground-based instrument network in Scandinavia. At ~21:17 UT during the recovery phase of the substorm, an <span class="hlt">auroral</span> streamer is detected by these instruments and the EISCAT radar, while simultaneously the Cluster satellites observe a bursty bulk flow in the conjugate portion of the plasma sheet in the magnetotail. Our combined data analysis reveals significant differences between the ionospheric equivalent current signature of this streamer within a double oval configuration, as compared to previously studied streamer events without such a configuration. We attribute these differences to the presence of an additional poleward polarization electric field between the poleward and the equatorward portions of the double oval, and show with a simple model that such an assumption can conceptually explain the observations. Further, we estimate the total current transferred in meridional direction by this recovery phase streamer to ~80 kA, significantly less than for previously analysed expansion phase streamer events. Both results indicate that the development of <span class="hlt">auroral</span> streamers is dependent on the ambient background conditions in the magnetosphere-ionosphere system. The <span class="hlt">auroral</span> streamer event studied was simultaneously observed in the conjugate Northern and Southern Hemisphere ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SSRv..187...23G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SSRv..187...23G"><span id="translatedtitle">A Brief Review of Ultraviolet <span class="hlt">Auroral</span> Emissions on Giant Planets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grodent, Denis</p> <p>2015-04-01</p> <p>The morphologies of the ultraviolet <span class="hlt">auroral</span> emissions on the giant gas planets, Jupiter and Saturn, have conveniently been described with combinations of a restricted number of basic components. Although this simplified view is very handy for a gross depiction of the giant planets' aurorae, it fails to scrutinize the diversity and the dynamics of the actual features that are regularly observed with the available ultraviolet imagers and spectrographs. In the present review, the typical morphologies of Jupiter and Saturn's aurorae are represented with an updated and more accurate set of components. The use of sketches, rather than images, makes it possible to compile all these components in a single view and to put aside ultraviolet imaging technical issues that are blurring the emission sources, thus preventing one from disentangling the different <span class="hlt">auroral</span> signatures. The ionospheric and magnetospheric processes to which these <span class="hlt">auroral</span> features allude can then be more easily accounted. In addition, the use of components of the same kind for both planets may help to put forward similarities and differences between Jupiter and Saturn. The case of the ice giants Uranus and Neptune is much less compelling since their weak <span class="hlt">auroral</span> emissions are very poorly documented and one can only speculate about their origin. This review presents a current perspective that will inevitably evolve in the future, especially with upcoming observing campaigns and forthcoming missions like Juno.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM53A2215U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM53A2215U"><span id="translatedtitle">New frontiers in H-Beta <span class="hlt">auroral</span> photometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Unick, C.; Donovan, E.; Connors, M. G.; Spanswick, E.; Jackel, B. J.; Greffen, M. J.; Wilson, C.; Little, J.; Chaddock, D.; Schofield, I.; MacRae, A.; Chen, S.; Crowther, A.; James, S.; Read, A.; Willis, T.</p> <p>2013-12-01</p> <p>The proton aurora provides valuable information about magnetotail structure and dynamics. For example, the location of the equatorward boundary of the proton aurora is a robust indicator of magnetotail stretching. Also, proton <span class="hlt">auroral</span> luminosities combined with in situ ion measurements provide important information about magnetic mapping between the inner CPS and the <span class="hlt">auroral</span> ionosphere. In this paper, we present a new and innovative proton-<span class="hlt">auroral</span> (H-Beta) meridian-scanning photometer (MSP) capable of higher spatial and temporal resolution than has been achieved in the past. This H-Beta MSP is the first of a new dual-wavelength (signal/background) MSP design with a single scanning mirror and no other moving parts. The novel filtering architecture allows for a near 100% duty cycle with a 30-second meridian scan and configurable operating modes. The new design is significantly more sensitive than the legacy CANOPUS MSPs. The increased SNR can be employed in a variety of ways, such as to achieve significantly higher time resolution. Here, we present the new instrument design, test data from a commissioning campaign in Athabasca, and some thoughts on how the enhance proton <span class="hlt">auroral</span> capability can increase the science value of these measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006JGRA..111.4201Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006JGRA..111.4201Z&link_type=ABSTRACT"><span id="translatedtitle">Characteristic ion distributions in the dynamic <span class="hlt">auroral</span> transition region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zeng, W.; Horwitz, J. L.; Tu, J.-N.</p> <p>2006-04-01</p> <p>A Dynamic Fluid Kinetic (DyFK) simulation is conducted to study the H+/O+ flows and distribution functions in the high-latitude dynamic transition region, specifically from 1000 km to about 4000 km altitude. Here, the collisional-to-collisionless transition region is that region where Coulomb collisions have significant but not dominant effects on the ion distributions. In this study, a simulation flux tube, which extends from 120 km to 3 RE altitude, is assumed to experience a pulse of <span class="hlt">auroral</span> effects for approximately 20 minutes, including both soft electron precipitation and transverse wave heating, and then according to different geophysical circumstances, either to relax following the cessation of such <span class="hlt">auroral</span> effects or to be heated further continuously by waves with power at higher frequencies. Our principal purpose in this investigation is to elicit the characteristic ion distribution functions in the <span class="hlt">auroral</span> transition region, where both collisions and kinetic processes play significant roles. The characteristics of the simulated O+ and H+ velocity distributions, such as kidney bean shaped H+ distributions, and O+ distributions having cold cores with upward folded conic wings, resemble those observed by satellites at similar altitudes and geographic conditions. From the simulated distribution function results under different geophysical conditions, we find that O+-O+ and O+-H+ collisions, in conjunction with the kinetic and <span class="hlt">auroral</span> processes, are key factors in the velocity distributions up to 4000 km altitude, especially for the low speed portions, for both O+ and H+ ions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820063781&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dcalvert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820063781&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dcalvert"><span id="translatedtitle">A feedback model for the source of <span class="hlt">auroral</span> kilometric radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Calvert, W.</p> <p>1982-01-01</p> <p>It is noted that in order to compensate for the wave refraction inside the source, the boundary reflection surfaces must converge with altitude, and this implies that the most likely <span class="hlt">auroral</span> kilometric radiation source would be a thin, local density enhancement, since the refractive index contours at its boundaries would be expected to slope inward. The ISEE observations of multiple spectral components, which are attributed to separate oscillations at different altitudes in the same enhancement, indicate a source thickness as small as 25 km and an internal wave growth threshold of roughly 40 dB, rather than the 70-120 dB previously believed necessary to account for <span class="hlt">auroral</span> kilometric radiation without feedback. What is considered more significant is that the feedback model accounts for numerous aspects of the <span class="hlt">auroral</span> kilometric radiation behavior, predicts emission at the wave growth saturation level, and leads to the conclusion that <span class="hlt">auroral</span> kilometric radiation originates at many compact sites, each emitting a nearly monochromatic wave.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050210157','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050210157"><span id="translatedtitle">Eyewitness Reports of the Great <span class="hlt">Auroral</span> Storm of 1859</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Green, James L.; Boardsen, Scott; Odenwald, Sten; Humble, John; Pazamickas, Katherine A.</p> <p>2005-01-01</p> <p>The great geomagnetic storm of 1859 is really composed of two closely spaced massive worldwide <span class="hlt">auroral</span> events. The first event began on August 28th and the second began on September 2nd. It is the storm on September 2nd that results from the Carrington-Hodgson white light flare that occurred on the sun September l&. In addition to published scientific measurements; newspapers, ship logs and other records of that era provide an untapped wealth of first hand observations giving time and location along with reports of the <span class="hlt">auroral</span> forms and colors. At its height, the aurora was described as a blood or deep crimson red that was so bright that one "could read a newspaper by." Several important aspects of this great geomagnetic storm are simply phenomenal. <span class="hlt">Auroral</span> forms of all types and colors were observed to latitudes of 25deg and lower. A significant portion of the world's 125,000 miles of telegraph lines were also adversely affected. Many of - which were unusable for 8 hours or more and had a small but notable economic impact. T h s paper presents only a select few available first hand accounts of the Great <span class="hlt">Auroral</span> Event of 1859 in an attempt to give the modern reader a sense of how this spectacular display was received by the public from many places around the globe and present some other important historical aspects of the storm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JASTP.145..114S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JASTP.145..114S&link_type=ABSTRACT"><span id="translatedtitle">Equatorward evolution of auroras from the poleward <span class="hlt">auroral</span> boundary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saka, O.; Hayashi, K.; Thomsen, M. F.</p> <p>2016-07-01</p> <p>An all-sky imager installed at the midnight sector in Dawson City (66.0° in geomagnetic latitude) recorded the equatorward evolution of auroras from the <span class="hlt">auroral</span> poleward boundary. The auroras evolved as shear layers expanding southeastward with velocities of 1-4 km/s, referred to as N-S auroras, and occurred during the transient intensification of the convection electric fields in the nighttime magnetosphere, as inferred from an electron spectrogram at geosynchronous altitudes. A continuous increase in the inclination angle of the field lines and magnetic field perturbations associated with propagating ionospheric loop currents were observed in the <span class="hlt">auroral</span> zone during the N-S auroras. Simultaneously, Pc4 pulsations were observed at low latitudes from night to day sectors. We conclude the following: (1) the N-S auroras are an <span class="hlt">auroral</span> manifestation of the earthward drift of plasma sheet electrons in the equatorial plane associated with transient and localized convection electric fields; (2) the Pc4 pulsations are produced in the magnetosphere by plasma sheet ions in the plasmasphere. The localized convection fields produce a vortical motion of plasmas in the equatorial plane, which may initiate the N-S auroras and ionospheric loop currents in the <span class="hlt">auroral</span> zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5931611','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5931611"><span id="translatedtitle">The response of thermospheric nitric oxide to an <span class="hlt">auroral</span> storm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Siskind, D.E.</p> <p>1988-01-01</p> <p>The response of thermospheric nitric oxide (NO) to the <span class="hlt">auroral</span> storm of September 19, 1984 is analyzed. Measurements of nitric oxide from the Solar Mesosphere Explorer (SME) ultraviolet spectrometer are compared with the calculations of a one-dimensional photochemical model of the lower thermosphere. The NCAR Thermospheric General Circulation Model (TGCM) is used to calculate the response of the background neutral atmosphere to <span class="hlt">auroral</span> forcings such as Joule and particle heating. The output of the TGCM is used as input to the photochemical model. The time history of the <span class="hlt">auroral</span> energy input is assessed using particle data from the NOAA 6 and 7 satellites. The SME NO measurements were made from 100 km to 140 km along two orbital tracks: one over the United States and one over Europe. The observations show a factor of 3 increase in NO at <span class="hlt">auroral</span> latitudes for both orbits as a result of the storm. Nitric oxide at mid-latitudes also increased by a factor of 3 but only over the United States. Calculations of the mid-latitude NO response show that temperature increases which result from Joule heating lead to NO enhancements. A larger response is initially seen for altitudes greater than 120 km.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6499218','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6499218"><span id="translatedtitle">Equatorward and poleward expansion of the auroras during <span class="hlt">auroral</span> substorms</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nakamura, R. ); Oguti, Takasi ); Yamamoto, Tatsundo ); Kokubun, Susumu )</p> <p>1993-04-01</p> <p>The authors have used all-sky TV <span class="hlt">auroral</span> data from a number of different sources to study the formation of the <span class="hlt">auroral</span> bulge with high spatial and temporal resolution. By linking data sets which cover different parts of the sky they are able to study systematically the development of structures within the poleward expanding bulge. Structures develop to the west, east, and equatorward from a localized region of breakup. To the west a surge develops with a clockwise rotation (when viewed along the magnetic field direction). To the east thin <span class="hlt">auroral</span> features propagate toward the east. Near the center of the bulge, <span class="hlt">auroral</span> features develop equatorward, becoming north-south aligned. These and other observations are suggested to be the consequence of the bulge developing along the plasma steamlines as a two cell equipotential distribution. In terms of this model the authors are able to explain the expansions of the bulge in different directions, the observation of pulsating structures in the aurora, and offer explanations of other observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E2729H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E2729H"><span id="translatedtitle">Comparison of <span class="hlt">auroral</span> structures at Earth and Jupiter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hill, T.</p> <p></p> <p>Bright, well-defined <span class="hlt">auroral</span> structures generally mark the presence of strong upward Birkeland (magnetic-field-aligned) currents which couple the magnetosphere to the planetary ionosphere. These Birkeland currents tend to flow in sheets aligned with strong velocity shear layers in the magnetospheric plasma flow as mapped to the ionosphere. At Earth, velocity shear layers are produced in the magnetosphere's response to solar-wind forcing, and occur near the topological separator surface between open and closed magnetic field lines. At Jupiter, strong velocity shear is produced by internal magnetospheric processes far removed from the open-closed boundary. These processes include the enforcement of partial corotation of magnetospheric plasma, responsible for the "main oval" aurora, and the electrodynamic coupling of Jupiter to its Galilean moons, responsible for <span class="hlt">auroral</span> spots at the magnetic footprints of Io, Europa, and Ganymede, and an <span class="hlt">auroral</span> tail downstream of Io. Both planets also exhibit "polar-cap" <span class="hlt">auroral</span> structures that share at least two features in common: they are more time-variable than the oval emissions, and their origins are not understood.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22149309','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22149309"><span id="translatedtitle">Fractal approach to the description of the <span class="hlt">auroral</span> region</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chernyshov, A. A. Mogilevsky, M. M.; Kozelov, B. V.</p> <p>2013-07-15</p> <p>The plasma of the <span class="hlt">auroral</span> region, where energetic particles precipitate from the magnetosphere into the ionosphere, is highly inhomogeneous and nonstationary. In this case, traditional methods of classical plasma physics turn out to be inapplicable. In order to correctly describe the dynamic regimes, transition processes, fluctuations, and self-similar scalings in this region, nonlinear dynamics methods based of the concepts of fractal geometry and percolation theory can be used. In this work, the fractal geometry and percolation theory are used to describe the spatial structure of the ionospheric conductivity. The topological properties, fractal dimensions, and connective indices characterizing the structure of the Pedersen and Hall conductivities on the nightside <span class="hlt">auroral</span> zone are investigated theoretically. The restrictions imposed on the fractal estimates by the condition of ionospheric current percolation are analyzed. It is shown that the fluctuation scalings of the electric fields and <span class="hlt">auroral</span> glow observed in the <span class="hlt">auroral</span> zone fit well the restrictions imposed by the critical condition on the percolation of the Pedersen current. Thus, it is demonstrated that the fractal approach is a promising and convenient method for studying the properties of the ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Icar..268..145S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Icar..268..145S"><span id="translatedtitle">Stability within Jupiter's polar <span class="hlt">auroral</span> 'Swirl region' over moderate timescales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stallard, Tom S.; Clarke, John T.; Melin, Henrik; Miller, Steve; Nichols, Jon D.; O'Donoghue, James; Johnson, Rosie E.; Connerney, John E. P.; Satoh, Takehiko; Perry, Michael</p> <p>2016-04-01</p> <p>Jupiter's Swirl region, poleward of the main <span class="hlt">auroral</span> emission, has been characterised in previous observations as having highly variable <span class="hlt">auroral</span> emission, changing dramatically across the region on a two-minute timescale, the typical integration time for UV images. This variability has made comparisons with H3+ emission difficult. Here, we show that the Swirl region in H3+ images is characterised by relatively stable emission, often with an arc of emission on the boundary between the Swirl and Dark regions. Coadding multiple UV images taken over the approximate lifetime of the H3+ molecule in the ionosphere, show similar structures to those observed in the H3+ images. Our analysis shows that UV <span class="hlt">auroral</span> morphology within Jupiter's Swirl region is only highly variable on short timescales of ∼100 s, an intrinsic property of the particle precipitation process, but this variability drops away on timescales of 5-15 min. On moderate timescales between 10 and 100 min, the Swirl region is stable, evolving through as yet unknown underlying magnetospheric interactions. This shows that observing the UV aurora over timescales 5-15 min resolves clear <span class="hlt">auroral</span> structures that will help us understand the magnetospheric origin of these features, and that calculating the variability over different timescales, especially >15 min, provides a new and important new tool in our understanding of Jupiter's polar aurora.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010081949','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010081949"><span id="translatedtitle">Kinetic Alfven Wave Electron Acceleration on <span class="hlt">Auroral</span> Field Lines</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kletzing, Craig A.</p> <p>2001-01-01</p> <p>Major results of the S3-3 Langmuir sweep study are published. Studies show statistics and average density and temperature variation on <span class="hlt">auroral</span> field lines up to 8000 km altitude. Alfven wave papers were published. Our model of Alfven wave propagation on <span class="hlt">auroral</span> field lines was successfully extended to handle varying density and magnetic field for the inertial mode. The study showed that Alfven wave can create time-dispersed electron signatures. A study was undertaken to extend Langmuir sweep I-V curves to handle the case of an kappa electron distribution as well as Maxwellian. The manuscript is in preparation. Participated in International Space Science Institute study of Alfvenic structures which resulted in a group review paper. The proposed work was to develop an extended model of Alfven wave propagation along <span class="hlt">auroral</span> field lines to study electron acceleration. As part of this work, a major task was to characterize density and temperature along <span class="hlt">auroral</span> field lines by using spacecraft Langmuir sweep data. The work that was completed under this funding was successful at both tasks. Three papers have been published as part of this work and a fourth manuscript is in preparation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820028333&hterms=1087&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231087','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820028333&hterms=1087&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231087"><span id="translatedtitle">Correlations between solar wind parameters and <span class="hlt">auroral</span> kilometric radiation intensity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gallagher, D. L.; Dangelo, N.</p> <p>1981-01-01</p> <p>The relationship between solar wind properties and the influx of energy into the nightside <span class="hlt">auroral</span> region as indicated by the intensity of <span class="hlt">auroral</span> kilometric radiation is investigated. Smoothed Hawkeye satellite observations of <span class="hlt">auroral</span> radiation at 178, 100 and 56.2 kHz for days 160 through 365 of 1974 are compared with solar wind data from the composite Solar Wind Plasma Data Set, most of which was supplied by the IMP-8 spacecraft. Correlations are made between smoothed daily averages of solar wind ion density, bulk flow speed, total IMF strength, electric field, solar wind speed in the southward direction, solar wind speed multiplied by total IMF strength, the substorm parameter epsilon and the Kp index. The greatest correlation is found between solar wind bulk flow speed and <span class="hlt">auroral</span> radiation intensity, with a linear correlation coefficient of 0.78 for the 203 daily averages examined. A possible mechanism for the relationship may be related to the propagation into the nightside magnetosphere of low-frequency long-wavelength electrostatic waves produced in the magnetosheath by the solar wind.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title20-vol2/pdf/CFR-2013-title20-vol2-sec401-165.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title20-vol2/pdf/CFR-2013-title20-vol2-sec401-165.pdf"><span id="translatedtitle">20 CFR 401.165 - Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-04-01</p> <p>... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>. 401.165... RECORDS AND INFORMATION Disclosure of Official Records and Information § 401.165 Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>. (a) General. Statistical and <span class="hlt">research</span> <span class="hlt">activities</span> often do not require information in a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title20-vol2/pdf/CFR-2012-title20-vol2-sec401-165.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title20-vol2/pdf/CFR-2012-title20-vol2-sec401-165.pdf"><span id="translatedtitle">20 CFR 401.165 - Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-04-01</p> <p>... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>. 401.165... RECORDS AND INFORMATION Disclosure of Official Records and Information § 401.165 Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>. (a) General. Statistical and <span class="hlt">research</span> <span class="hlt">activities</span> often do not require information in a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title20-vol2/pdf/CFR-2014-title20-vol2-sec401-165.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title20-vol2/pdf/CFR-2014-title20-vol2-sec401-165.pdf"><span id="translatedtitle">20 CFR 401.165 - Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-04-01</p> <p>... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>. 401.165... RECORDS AND INFORMATION Disclosure of Official Records and Information § 401.165 Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>. (a) General. Statistical and <span class="hlt">research</span> <span class="hlt">activities</span> often do not require information in a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title20-vol2/pdf/CFR-2010-title20-vol2-sec401-165.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title20-vol2/pdf/CFR-2010-title20-vol2-sec401-165.pdf"><span id="translatedtitle">20 CFR 401.165 - Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-04-01</p> <p>... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>. 401.165... RECORDS AND INFORMATION Disclosure of Official Records and Information § 401.165 Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>. (a) General. Statistical and <span class="hlt">research</span> <span class="hlt">activities</span> often do not require information in a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title20-vol2/pdf/CFR-2011-title20-vol2-sec401-165.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title20-vol2/pdf/CFR-2011-title20-vol2-sec401-165.pdf"><span id="translatedtitle">20 CFR 401.165 - Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-04-01</p> <p>... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>. 401.165... RECORDS AND INFORMATION Disclosure of Official Records and Information § 401.165 Statistical and <span class="hlt">research</span> <span class="hlt">activities</span>. (a) General. Statistical and <span class="hlt">research</span> <span class="hlt">activities</span> often do not require information in a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140000893','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140000893"><span id="translatedtitle">Strong Magnetic Field Fluctuations within Filamentary <span class="hlt">Auroral</span> Density Cavities Interpreted as VLF Saucer Sources</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Knudsen, D. L.; Kabirzadeh, R.; Burchill, J. K.; Pfaff, Robert F.; Wallis, D. D.; Bounds, S. R.; Clemmons, J. H.; Pincon, J.-L.</p> <p>2012-01-01</p> <p>The Geoelectrodynamics and Electro-Optical Detection of Electron and SuprathermalIon Currents (GEODESIC) sounding rocket encountered more than 100 filamentary densitycavities associated with enhanced plasma waves at ELF (3 kHz) and VLF (310 kHz)frequencies and at altitudes of 800990 km during an <span class="hlt">auroral</span> substorm. These cavities weresimilar in size (20 m diameter in most cases) to so-called lower-hybrid cavities (LHCs)observed by previous sounding rockets and satellites; however, in contrast, many of theGEODESIC cavities exhibited up to tenfold enhancements in magnetic wave powerthroughout the VLF band. GEODESIC also observed enhancements of ELF and VLFelectric fields both parallel and perpendicular to the geomagnetic field B0 within cavities,though the VLF E field increases were often not as large proportionally as seen in themagnetic fields. This behavior is opposite to that predicted by previously published theoriesof LHCs based on passive scattering of externally incident <span class="hlt">auroral</span> hiss. We argue thatthe GEODESIC cavities are <span class="hlt">active</span> wave generation sites capable of radiating VLF wavesinto the surrounding plasma and producing VLF saucers, with energy supplied by cold,upward flowing electron beams composing the <span class="hlt">auroral</span> return current. This interpretation issupported by the observation that the most intense waves, both inside and outside cavities,occurred in regions where energetic electron precipitation was largely inhibited orabsent altogether. We suggest that the wave-enhanced cavities encountered by GEODESICwere qualitatively different from those observed by earlier spacecraft because of thefortuitous timing of the GEODESIC launch, which placed the payload at apogee within asubstorm-related return current during its most intense phase, lasting only a few minutes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRA..117.2217K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRA..117.2217K"><span id="translatedtitle">Strong magnetic field fluctuations within filamentary <span class="hlt">auroral</span> density cavities interpreted as VLF saucer sources</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Knudsen, D. J.; Kabirzadeh, R.; Burchill, J. K.; Pfaff, R. F.; Wallis, D. D.; Bounds, S. R.; Clemmons, J. H.; Pinçon, J.-L.</p> <p>2012-02-01</p> <p>The Geoelectrodynamics and Electro-Optical Detection of Electron and Suprathermal Ion Currents (GEODESIC) sounding rocket encountered more than 100 filamentary density cavities associated with enhanced plasma waves at ELF (<3 kHz) and VLF (3-10 kHz) frequencies and at altitudes of 800-990 km during an <span class="hlt">auroral</span> substorm. These cavities were similar in size (˜20 m diameter in most cases) to so-called lower-hybrid cavities (LHCs) observed by previous sounding rockets and satellites; however, in contrast, many of the GEODESIC cavities exhibited up to tenfold enhancements in magnetic wave power throughout the VLF band. GEODESIC also observed enhancements of ELF and VLF electric fields both parallel and perpendicular to the geomagnetic field B0 within cavities, though the VLF E field increases were often not as large proportionally as seen in the magnetic fields. This behavior is opposite to that predicted by previously published theories of LHCs based on passive scattering of externally incident <span class="hlt">auroral</span> hiss. We argue that the GEODESIC cavities are <span class="hlt">active</span> wave generation sites capable of radiating VLF waves into the surrounding plasma and producing VLF saucers, with energy supplied by cold, upward flowing electron beams composing the <span class="hlt">auroral</span> return current. This interpretation is supported by the observation that the most intense waves, both inside and outside cavities, occurred in regions where energetic electron precipitation was largely inhibited or absent altogether. We suggest that the wave-enhanced cavities encountered by GEODESIC were qualitatively different from those observed by earlier spacecraft because of the fortuitous timing of the GEODESIC launch, which placed the payload at apogee within a substorm-related return current during its most intense phase, lasting only a few minutes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990089688&hterms=relationship&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Drelationship%2Bv','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990089688&hterms=relationship&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Drelationship%2Bv"><span id="translatedtitle">Relationship of Topside Ionospheric Ion Outflows to <span class="hlt">Auroral</span> Forms and Precipitations, Plasma Waves, and Convection Observed by POLAR</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hirahara, M.; Horwitz, J. L.; Moore, T. E.; Germany, G. A.; Spann, J. F.; Peterson, W. K.; Shelley, E. G.; Chandler, M. O.; Giles, B. L.; Craven, P. D.; Pollock, C. J.; Gurnett, D. A.; Persoon, A. M.; Scudder, J. D.; Maynard, N. C.; Mozer, F. S.; Brittnacher, M. J.; Nagai, T.</p> <p>1997-01-01</p> <p>The POLAR satellite often observes upflowing ionospheric ions (UFls) in and near the <span class="hlt">auroral</span> oval on southern perigee (approximately 5000 km altitude) passes. We present the UFI features observed by the thermal ion dynamics experiment (TIDE) and the toroidal imaging mass-angle spectrograph (TIMAS) in the dusk-dawn sector under two different geomagnetic <span class="hlt">activity</span> conditions in order to elicit their relationships with <span class="hlt">auroral</span> forms, wave emissions, and convection pattern from additional POLAR instruments. During the <span class="hlt">active</span> interval, the ultraviolet imager (UVI) observed a bright discrete aurora on the dusk side after the substorm onset and then observed a small isolated aurora form and diffuse auroras on the dawn side during the recovery phase. The UFls showed clear conic distributions when the plasma wave instrument (PWI) detected strong broadband wave emissions below approximately 10 kHz, while no significant <span class="hlt">auroral</span> <span class="hlt">activities</span> were observed by UVI. At higher latitudes, the low-energy UFI conics gradually changed to the polar wind component with decreasing intensity of the broadband emissions. V-shaped <span class="hlt">auroral</span> kilometric radiation (AKR) signatures observed above approximately 200 kHz by PWI coincided with the region where the discrete aurora and the UFI beams were detected. The latitude of these features was lower than that of the UFI conics. During the observations of the UFI beams and conics, the lower-frequency fluctuations observed by the electric field instrument (EFI) were also enhanced, and the convection directions exhibited large fluctuations. It is evident that large electrostatic potential drops produced the precipitating electrons and discrete auroras, the UFI beams, and the AKR, which is also supported by the energetic plasma data from HYDRA. Since the intense broadband emissions were also observed with the UFIs. the ionospheric ions could be energized transversely before or during the parallel acceleration due to the potential drops.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999AIPC..485...18W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999AIPC..485...18W"><span id="translatedtitle">Nonlinear interactions of electromagnetic waves with the <span class="hlt">auroral</span> ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wong, Alfred Y.</p> <p>1999-09-01</p> <p>The ionosphere provides us with an opportunity to perform plasma experiments in an environment with long confinement times, very large-scale lengths, and no confining walls. The <span class="hlt">auroral</span> ionosphere with its nearly vertical magnetic field geometry is uniquely endowed with large amount of free energy from electron and ion precipitation along the magnetic field and mega-ampere current across the magnetic field. To take advantage of this giant outdoor laboratory, two facilities HAARP and HIPAS, with frequencies ranging from the radio to optical bands, are now available for <span class="hlt">active</span> probing of and interaction with this interesting region. The ponderomotive pressures from the self-consistent wave fields have produced significant local perturbations of density and particle distributions at heights where the incident EM frequency matches a plasma resonance. This paper will review theory and experiments covering the nonlinear phenomena of parametric decay instability to wave collapse processes. At HF frequencies plasma lenses can be created by preconditioning pulses to focus what is a normally divergent beam into a high-intensity spot to further enhance nonlinear phenomena. At optical wavelengths a large rotating liquid metal mirror is used to focus laser pulses up to a given height. Such laser pulses are tuned to the same wavelengths of selected atomic and molecular resonances, with resulting large scattering cross sections. Ongoing experiments on dual-site experiments and excitation of ELF waves will be presented. The connection of such basic studies to environmental applications will be discussed. Such applications include the global communication using ELF waves, the ozone depletion and remediation and the control of atmospheric CO2 through the use of ion cyclotron resonant heating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21210450','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21210450"><span id="translatedtitle">Nonlinear interactions of electromagnetic waves with the <span class="hlt">auroral</span> ionosphere</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wong, Alfred Y.</p> <p>1999-09-20</p> <p>The ionosphere provides us with an opportunity to perform plasma experiments in an environment with long confinement times, very large-scale lengths, and no confining walls. The <span class="hlt">auroral</span> ionosphere with its nearly vertical magnetic field geometry is uniquely endowed with large amount of free energy from electron and ion precipitation along the magnetic field and mega-ampere current across the magnetic field. To take advantage of this giant outdoor laboratory, two facilities HAARP and HIPAS, with frequencies ranging from the radio to optical bands, are now available for <span class="hlt">active</span> probing of and interaction with this interesting region. The ponderomotive pressures from the self-consistent wave fields have produced significant local perturbations of density and particle distributions at heights where the incident EM frequency matches a plasma resonance. This paper will review theory and experiments covering the nonlinear phenomena of parametric decay instability to wave collapse processes. At HF frequencies plasma lenses can be created by preconditioning pulses to focus what is a normally divergent beam into a high-intensity spot to further enhance nonlinear phenomena. At optical wavelengths a large rotating liquid metal mirror is used to focus laser pulses up to a given height. Such laser pulses are tuned to the same wavelengths of selected atomic and molecular resonances, with resulting large scattering cross sections. Ongoing experiments on dual-site experiments and excitation of ELF waves will be presented. The connection of such basic studies to environmental applications will be discussed. Such applications include the global communication using ELF waves, the ozone depletion and remediation and the control of atmospheric CO{sub 2} through the use of ion cyclotron resonant heating.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AnGeo..32.1333M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AnGeo..32.1333M"><span id="translatedtitle">Characteristics of Poker Flat Incoherent Scatter Radar (PFISR) naturally enhanced ion-acoustic lines (NEIALs) in relation to <span class="hlt">auroral</span> forms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Michell, R. G.; Grydeland, T.; Samara, M.</p> <p>2014-10-01</p> <p>Naturally enhanced ion-acoustic lines (NEIALs) have been observed with the Poker Flat Incoherent Scatter Radar (PFISR) ever since it began operating in 2006. The nearly continuous operation of PFISR since then has led to a large number of NEIAL observations from there, where common-volume, high-resolution <span class="hlt">auroral</span> imaging data are available. We aim to systematically distinguish the different types of <span class="hlt">auroral</span> forms that are associated with different NEIAL features, including spectral shape and altitude extent. We believe that NEIALs occur with a continuum of morphological characteristics, although we find that most NEIALs observed with PFISR fall into two general categories. The first group occurs at fairly low altitudes - F region or below - and have power at, and spread between, the ion-acoustic peaks. The second group contains the type of NEIALs that have previously been observed with the EISCAT radars, those that extend to high altitudes (600 km or more) and often have large asymmetries in the power enhancements between the two ion-acoustic shoulders. We find that there is a correlation between the <span class="hlt">auroral</span> structures and the type of NEIALs observed, and that the <span class="hlt">auroral</span> structures present during NEIAL events are consistent with the likely NEIAL generation mechanisms inferred in each case. The first type of NEIAL - low altitude - is the most commonly observed with PFISR and is most often associated with <span class="hlt">active</span>, structured <span class="hlt">auroral</span> arcs, such as substorm growth phase, and onset arcs and are likely generated by Langmuir turbulence. The second type of NEIAL - high altitude - occurs less frequently in the PFISR radar and is associated with aurora that contains large fluxes of low-energy electrons, as can happen in poleward boundary intensifications as well as at substorm onset and is likely the result of current-driven instabilities and in some cases Langmuir turbulence as well. In addition, a preliminary <span class="hlt">auroral</span> photometry analysis revealed that there is an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=bridges+AND+type&id=EJ917890','ERIC'); return false;" href="http://eric.ed.gov/?q=bridges+AND+type&id=EJ917890"><span id="translatedtitle">Action <span class="hlt">Research</span> as a Professional Development <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>West, Chad</p> <p>2011-01-01</p> <p>Reflective teachers are always searching for ways to improve their teaching. When this reflection becomes intentional and systematic, they are engaging in teacher <span class="hlt">research</span>. This type of <span class="hlt">research</span>, sometimes called "action <span class="hlt">research</span>", can help bridge the gap between theory and practice by addressing topics that are relevant to practicing teachers.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011JGRA..116.4207P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011JGRA..116.4207P&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Auroral</span> electrojets during deep solar minimum at the end of solar cycle 23</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pulkkinen, T. I.; Tanskanen, E. I.; Viljanen, A.; Partamies, N.; Kauristie, K.</p> <p>2011-04-01</p> <p>We investigate the <span class="hlt">auroral</span> electrojet <span class="hlt">activity</span> during the deep minimum at the end of solar cycle 23 (2008-2009) by comparing data from the IMAGE magnetometer chain, <span class="hlt">auroral</span> observations in Fennoscandia and Svalbard, and solar wind and interplanetary magnetic field (IMF) observations from the OMNI database from that period with those recorded one solar cycle earlier. We examine the eastward and westward electrojets and the midnight sector separately. The electrojets during 2008-2009 were found to be weaker and at more poleward latitudes than during other times, but when similar driving solar wind and IMF conditions are compared, the behavior in the morning and evening sectors during 2008-2009 was similar to other periods. On the other hand, the midnight sector shows distinct behavior during 2008-2009: for similar driving conditions, the electrojets resided at further poleward latitudes and on average were weaker than during other periods. Furthermore, the substorm occurrence frequency seemed to saturate to a minimum level for very low levels of driving during 2009. This analysis suggests that the solar wind coupling to the ionosphere during 2008-2009 was similar to other periods but that the magnetosphere-ionosphere coupling has features that are unique to this period of very low solar <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6193453','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6193453"><span id="translatedtitle">Coherence scales of wavefield during propagation through naturally disturbed ionosphere in the polar cap, <span class="hlt">auroral</span>, and equatorial regions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Basu, S.; Basu, S.; Livingston, R.C.</p> <p>1990-05-03</p> <p>Phase and intensity scintillation measurements have been made at low latitudes in the equatorial anomaly region, and at high latitudes in the <span class="hlt">auroral</span> oval and the polar cap regions, using phase coherent transmissions at 250 MHz from stationary and near stationary satellites. The observations pertain to periods of high solar <span class="hlt">activity</span> when intense scintillation <span class="hlt">activity</span> is recorded at each of the above observing sites. This data set has been utilized to study the reduction of coherence times of intensity and complex amplitude scintillation with increasing strength of scattering. Estimates of coherence scales of intensity and complex amplitude scintillation at 250 MHz are provided which indicate that coherent scales of scintillation are typically of the order of hundreds of meters at high latitudes but approach values as small as tens of meters in the equatorial anomaly region. The phase spectral index in the nightside <span class="hlt">auroral</span> oval is observed to be much steeper (p sub psi = .4) than those typically observed in the equatorial (p sub psi = 2.4) or polar cap regions (p sub psi approx. -2.3). It shows the importance of large scale phase variations in the nightside <span class="hlt">auroral</span> oval. Under strong scatter conditions, the coherence times of complex amplitude scintillation are shown to asymptotically approach a value which is 1.4 times the coherence time of intensity scintillation. This result is consistent with the theoretical predictions for Rayleigh statistics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMSA51B0246K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMSA51B0246K"><span id="translatedtitle">Auroras Now! - <span class="hlt">Auroral</span> nowcasting service for Hotels in Finnish Lapland and its performance during winter 2003-2004</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kauristie, K.; Mälkki, A.; Pulkkinen, A.; Nevanlinna, H.; Ketola, A.; Tulkki, V.; Raita, T.; Blanco, A.</p> <p>2004-12-01</p> <p>European Space Agency is currently supporting 17 Service Development <span class="hlt">Activities</span> (SDA) within its Space Weather Pilot Project. Auroras Now!, one of the SDAs, has been operated during November 2003 - March 2004 as its pilot season. The service includes a public part freely accessible in Internet (http://aurora.fmi.fi) and a private part visible only to the customers of two hotels in the Finnish Lapland through the hotels' internal TV-systems. The nowcasting system is based on the magnetic recordings of two geophysical observatories, Sodankylä (SOD, MLAT ~64 N) and Nurmijärvi (NUR, MLAT ~57 N). The probability of <span class="hlt">auroral</span> occurrence is continuously characterised with an empirically determined three-level scale. The index is updated once per hour and based on the magnetic field variations recorded at the observatories. During dark hours the near-real time <span class="hlt">auroral</span> images acquired at SOD are displayed. The hotel service also includes cloudiness predictions for the coming night. During the pilot season the reliability of the three-level magnetic alarm system was weekly evaluated by comparing its prediction with <span class="hlt">auroral</span> observations by the nearby all-sky camera. Successful hits and failures were scored according to predetermined rules. The highest credit points when it managed to spot auroras in a timely manner and predict their brightness correctly. Maximum penalty points were given when the alarm missed clear bright auroras lasting for more than one hour. In this presentation we analyse the results of the evaluation, present some ideas to further sharpen the procedure, and discuss more generally the correlation between local <span class="hlt">auroral</span> and magnetic <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM51E4281A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM51E4281A"><span id="translatedtitle">Altitude Distribution and Position of <span class="hlt">Auroral</span> Density Cavities in the <span class="hlt">Auroral</span> Acceleration Region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alm, L.; Li, B.; Marklund, G. T.; Karlsson, T.</p> <p>2014-12-01</p> <p>We have investigated the statistical distribution of <span class="hlt">auroral</span> density cavities (ADC) in the <span class="hlt">auroral</span> acceleration region (AAR) using data from the Cluster satellites. The data was collected from 2002 to 2007, at geocentric altitudes of 3.0-6.5 RE and 60-80 degrees invariant latitude. All time intervals containing upward ion beams events were manually inspected for the presence of inverted-V electrons and the spacecraft potential determined as a proxy for the electron density. The parallel potential drops above and below the satellite was estimated in order to determine the satellite's position relative the AAR. Between 4.0 and 5.5 RE several crossings of the upper edge of the AAR were observed. The maximum rate of occurrence was found between 4.75 and 5.0 RE. Between 3.75 and 6.5 RE many of the events exhibits an ion beam but no inverted-V electrons. This is consistent with the satellite being located inside the flux tube of the AAR but above the AAR. A sharp increase in the occurrence rate of ion beams without inverted-V electrons is found above 5.25 RE. The maximum occurrence rate is found between 6 and 6.5 REwhere none of the events exhibits any inverted-V. The spacecraft potential exhibits a monotonic decrease with the geocentric altitude, though the rate of decrease is very small between 4.5 and 5.75 RE. Above 5.75 RE, where a large number of events do not exhibit any inverted-V electrons, the spacecraft potential exhibits a rapid decrease. This is consistent with entering a distinct region of low electron densities. The observations indicate that the AAR extends considerably higher that the 2.0-3.0 RE which is often cited. The region between 4.5 and 5.75 RE appears to be a transition region based on the behavior of the spacecraft potential and loss of inverted-V electrons. We interpret this as being the upper edge of the AAR. However, the ADC does not appear to be confined by the AAR and will in many cases both extend above the AAR and in many cases become more</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMSA21C0377M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMSA21C0377M"><span id="translatedtitle">ELF/VLF Waves Generated by an Artificially-Modulated <span class="hlt">Auroral</span> Electrojet Above the HAARP HF Transmitter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moore, R. C.; Inan, U. S.; Bell, T. F.</p> <p>2004-12-01</p> <p>Naturally-forming, global-scale currents, such as the polar electrojet current and the mid-latitude dynamo, have been used as current sources to generate electromagnetic waves in the Extremely Low Frequency (ELF) and Very Low Frequency (VLF) bands since the 1970's. While many short-duration experiments have been performed, no continuous multi-week campaign data sets have been published providing reliable statistics for ELF/VLF wave generation. In this paper, we summarize the experimental data resulting from multiple ELF/VLF wave generation campaigns conducted at the High-frequency <span class="hlt">Active</span> <span class="hlt">Auroral</span> <span class="hlt">Research</span> Project (HAARP) HF transmitter in Gakona, Alaska. For one 14-day period in March, 2002, and one 24-day period in November, 2002, the HAARP HF transmitter broadcast ELF/VLF wave generation sequences for 10 hours per day, between 0400 and 1400 UT. Five different modulation frequencies broadcast separately using two HF carrier frequencies are examined at receivers located 36, 44, 147, and 155 km from the HAARP facility. Additionally, a continuous 24-hour transmission period is analyzed to compare day-time wave generation to night-time wave generation. Lastly, a power-ramping scheme was employed to investigate possible thresholding effects at the wave-generating altitude. Wave generation statistics are presented along with source-region property calculations performed using a simple model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED537583.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED537583.pdf"><span id="translatedtitle">Fitness and Physical <span class="hlt">Activity</span>. <span class="hlt">Research</span> Brief</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Walker, Karen</p> <p>2005-01-01</p> <p>What can be done to support fitness and physical <span class="hlt">activity</span>? Schools can guide students in developing life-long habits of participating in physical <span class="hlt">activities</span>. According to the National Association for Sports and Physical Education, the concepts of physical fitness <span class="hlt">activities</span> and physical education are used synonymously, however, they are not the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=plant+AND+respiration&pg=4&id=ED387322','ERIC'); return false;" href="http://eric.ed.gov/?q=plant+AND+respiration&pg=4&id=ED387322"><span id="translatedtitle">Biology <span class="hlt">Research</span> <span class="hlt">Activities</span>: Teacher's Edition (with Answers).</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Newman, Barbara</p> <p></p> <p>This book is part of the series "Explorations in Science" which contains enrichment <span class="hlt">activities</span> for the general science curriculum. Each book in the series contains innovative and traditional projects for both the bright and average, the self-motivated, and those who find <span class="hlt">activity</span> motivating. Each <span class="hlt">activity</span> is self-contained and provides everything…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title38-vol1/pdf/CFR-2013-title38-vol1-sec1-488.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title38-vol1/pdf/CFR-2013-title38-vol1-sec1-488.pdf"><span id="translatedtitle">38 CFR 1.488 - <span class="hlt">Research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>....S.C. 5701, 38 CFR 1.500-1.527, the Privacy Act (5 U.S.C. 552a), 38 CFR 1.575-1.584 and the following... disclosed for the purpose of conducting scientific <span class="hlt">research</span>. (a) Information in individually identifiable... conducting scientific <span class="hlt">research</span> if the Under Secretary for Health or designee makes a determination that...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title38-vol1/pdf/CFR-2011-title38-vol1-sec1-488.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title38-vol1/pdf/CFR-2011-title38-vol1-sec1-488.pdf"><span id="translatedtitle">38 CFR 1.488 - <span class="hlt">Research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>....S.C. 5701, 38 CFR 1.500-1.527, the Privacy Act (5 U.S.C. 552a), 38 CFR 1.575-1.584 and the following... disclosed for the purpose of conducting scientific <span class="hlt">research</span>. (a) Information in individually identifiable... conducting scientific <span class="hlt">research</span> if the Under Secretary for Health or designee makes a determination that...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title38-vol1/pdf/CFR-2010-title38-vol1-sec1-488.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title38-vol1/pdf/CFR-2010-title38-vol1-sec1-488.pdf"><span id="translatedtitle">38 CFR 1.488 - <span class="hlt">Research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>....S.C. 5701, 38 CFR 1.500-1.527, the Privacy Act (5 U.S.C. 552a), 38 CFR 1.575-1.584 and the following... disclosed for the purpose of conducting scientific <span class="hlt">research</span>. (a) Information in individually identifiable... conducting scientific <span class="hlt">research</span> if the Under Secretary for Health or designee makes a determination that...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title38-vol1/pdf/CFR-2012-title38-vol1-sec1-488.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title38-vol1/pdf/CFR-2012-title38-vol1-sec1-488.pdf"><span id="translatedtitle">38 CFR 1.488 - <span class="hlt">Research</span> <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>....S.C. 5701, 38 CFR 1.500-1.527, the Privacy Act (5 U.S.C. 552a), 38 CFR 1.575-1.584 and the following... disclosed for the purpose of conducting scientific <span class="hlt">research</span>. (a) Information in individually identifiable... conducting scientific <span class="hlt">research</span> if the Under Secretary for Health or designee makes a determination that...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Studies+AND+Ethnomethodology.&pg=3&id=EJ625602','ERIC'); return false;" href="http://eric.ed.gov/?q=Studies+AND+Ethnomethodology.&pg=3&id=EJ625602"><span id="translatedtitle">Engaging Students in Qualitative <span class="hlt">Research</span> through Experiential Class <span class="hlt">Activities</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Fontes, Lisa Aronson; Piercy, Fred P.</p> <p>2000-01-01</p> <p>Discusses the experiential <span class="hlt">activities</span> that are used in a graduate course on qualitative <span class="hlt">research</span> that addresses focus groups, observation, data collection, cultural sensitivity, ethnomethodology, data analysis, and morals and ethics in <span class="hlt">research</span>. Explains that students participate in an <span class="hlt">activity</span> in which they defend qualitative <span class="hlt">research</span>. (CMK)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=adapted+AND+physical+AND+activity&id=EJ971031','ERIC'); return false;" href="http://eric.ed.gov/?q=adapted+AND+physical+AND+activity&id=EJ971031"><span id="translatedtitle">Creating Evidence-Based <span class="hlt">Research</span> in Adapted Physical <span class="hlt">Activity</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Reid, Greg; Bouffard, Marcel; MacDonald, Catherine</p> <p>2012-01-01</p> <p>Professional practice guided by the best <span class="hlt">research</span> evidence is a usually referred to as evidence-based practice. The aim of the present paper is to describe five fundamental beliefs of adapted physical <span class="hlt">activity</span> practices that should be considered in an 8-step <span class="hlt">research</span> model to create evidence-based <span class="hlt">research</span> in adapted physical <span class="hlt">activity</span>. The five…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.5241O&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.5241O&link_type=ABSTRACT"><span id="translatedtitle">In-situ observation of electron kappa distributions associated with discrete <span class="hlt">auroral</span> arcs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ogasawara, Keiichi; Livadiotis, George; Samara, Marilia; Michell, Robert; Grubbs, Guy</p> <p>2016-04-01</p> <p>The Medium-energy Electron SPectrometer (MESP) sensor aboard a NASA sounding rocket was launched from Poker Flat <span class="hlt">Research</span> Range on 3 March 2014 as a part of Ground-to-Rocket Electrodynamics-Electrons Correlative Experiment (GREECE) mission. GREECE targeted to discover convergent E-field structures at low altitude ionosphere to find their contribution to the rapid fluid-like structures of aurora, and MESP successfully measured the precipitating electrons from 2 to 200 keV within multiple discrete <span class="hlt">auroral</span> arcs with the apogee of 350 km. MESP's unprecedented electron energy acceptance and high geometric factor made it possible to investigate precise populations of the suprathermal components measured in the inverted-V type electron energy distributions. The feature of these suprathermal electrons are explained by the kappa distribution functions with the parameters (densty, temperature, and kappa) consistent with the near-Earth tail plasma sheet, suggesting the source population of the <span class="hlt">auroral</span> electrons. The kappa-values are different between each arc observed as a function of latitude, but are almost stable within one discrete arc. We suggest that this transition of kappa reflects the probagation history of source electrons through the plasma sheet by changing its state from non-equilibrium electron distributions to thermal ones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27250414','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27250414"><span id="translatedtitle">Development and performance of a suprathermal electron spectrometer to study <span class="hlt">auroral</span> precipitations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ogasawara, Keiichi; Grubbs, Guy; Michell, Robert G; Samara, Marilia; Stange, Jason L; Trevino, John A; Webster, James; Jahn, Jörg-Micha</p> <p>2016-05-01</p> <p>The design, development, and performance of Medium-energy Electron SPectrometer (MESP), dedicated to the in situ observation of suprathermal electrons in the <span class="hlt">auroral</span> ionosphere, are summarized in this paper. MESP employs a permanent magnet filter with a light tight structure to select electrons with proper energies guided to the detectors. A combination of two avalanche photodiodes and a large area solid-state detector (SSD) provided 46 total energy bins (1 keV resolution for 3-20 keV range for APDs, and 7 keV resolution for >20 keV range for SSDs). Multi-channel ultra-low power application-specific integrated circuits are also verified for the flight operation to read-out and analyze the detector signals. MESP was launched from Poker Flat <span class="hlt">Research</span> Range on 3 March 2014 as a part of ground-to-rocket electrodynamics-electrons correlative experiment (GREECE) mission. MESP successfully measured the precipitating electrons from 3 to 120 keV in 120-ms time resolution and characterized the features of suprathermal distributions associated with <span class="hlt">auroral</span> arcs throughout the flight. The measured electrons were showing the inverted-V type spectra, consistent with the past measurements. In addition, investigations of the suprathermal electron population indicated the existence of the energetic non-thermal distribution corresponding to the brightest aurora. PMID:27250414</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RScI...87e3307O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RScI...87e3307O"><span id="translatedtitle">Development and performance of a suprathermal electron spectrometer to study <span class="hlt">auroral</span> precipitations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ogasawara, Keiichi; Grubbs, Guy; Michell, Robert G.; Samara, Marilia; Stange, Jason L.; Trevino, John A.; Webster, James; Jahn, Jörg-Micha</p> <p>2016-05-01</p> <p>The design, development, and performance of Medium-energy Electron SPectrometer (MESP), dedicated to the in situ observation of suprathermal electrons in the <span class="hlt">auroral</span> ionosphere, are summarized in this paper. MESP employs a permanent magnet filter with a light tight structure to select electrons with proper energies guided to the detectors. A combination of two avalanche photodiodes and a large area solid-state detector (SSD) provided 46 total energy bins (1 keV resolution for 3-20 keV range for APDs, and 7 keV resolution for >20 keV range for SSDs). Multi-channel ultra-low power application-specific integrated circuits are also verified for the flight operation to read-out and analyze the detector signals. MESP was launched from Poker Flat <span class="hlt">Research</span> Range on 3 March 2014 as a part of ground-to-rocket electrodynamics-electrons correlative experiment (GREECE) mission. MESP successfully measured the precipitating electrons from 3 to 120 keV in 120-ms time resolution and characterized the features of suprathermal distributions associated with <span class="hlt">auroral</span> arcs throughout the flight. The measured electrons were showing the inverted-V type spectra, consistent with the past measurements. In addition, investigations of the suprathermal electron population indicated the existence of the energetic non-thermal distribution corresponding to the brightest aurora.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950029563&hterms=fac&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dfac','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950029563&hterms=fac&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dfac"><span id="translatedtitle">Electrodynamic parameters in the nighttime sector during <span class="hlt">auroral</span> substorms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fujii, R.; Hoffman, R. A.; Anderson, P. C.; Craven, J. D.; Sugiura, M.; Frank, L. A.; Maynard, N. C.</p> <p>1994-01-01</p> <p>The characteristics of the large-scale electrodynamic parameters, field-aligned currents (FACs), electric fields, and electron precipitation, which are associated with <span class="hlt">auroral</span> substorm events in the nighttime sector, have been obtained through a unique analysis which places the ionospheric measurements of these parameters into the context of a generic substorm determined from global <span class="hlt">auroral</span> images. A generic bulge-type <span class="hlt">auroral</span> emission region has been deduced from <span class="hlt">auroral</span> images taken by the Dynamics Explorer 1 (DE 1) satellite during a number of isolated substorms, and the form has been divided into six sectors, based on the peculiar emission characteristics in each sector: west of bulge, surge horn, surge, middle surge, eastern bulge, and east of bulge. By comparing the location of passes of the Dynamics Explorer 2 (DE 2) satellite to the simultaneously obtained <span class="hlt">auroral</span> images, each pass is placed onto the generic aurora. The organization of DE 2 data in this way has systematically clarified peculiar characteristics in the electrodynamic parameters. An upward net current mainly appears in the surge, with little net current in the surge horn and the west of bulge. The downward net current is distributed over wide longitudinal regions from the eastern bulge to the east of bulge. Near the poleward boundary of the expanding <span class="hlt">auroral</span> bulge, a pair of oppositely directed FAC sheets is observed, with the downward FAC on the poleward side. This downward FAC and most of the upward FAC in the surge and the middle surge are assoc iated with narrow, intense antisunwqard convection, corresponding to an equatorward directed spikelike electric field. This pair of currents decreases in amplitude and latitudinal width toward dusk in the surge and the west of bulge, and the region 1 and 2 FACs become embedded in the sunward convection region. The upward FAC region associated with the spikelike field on the poleward edge of the bulge coincides well with intense electron</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EPSC....9..398N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EPSC....9..398N"><span id="translatedtitle">Modelling <span class="hlt">auroral</span> currents at hot Jupiters: implications for <span class="hlt">auroral</span> radio emissions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nichols, J. D.; Milan, S. E.</p> <p>2014-04-01</p> <p>Recently, the radio emissions of exoplanets have come under focus due to the commencement of observations using new radio telescopes such as LOFAR. A class of planet which has attracted significant attention in this respect is the close-orbiting 'hot Jupiter', several of which, according to previous estimates, may produce detectable radio emissions driven by stellar windmagnetosphere interactions. However, this expectation rests on the accuracy over many orders of magnitude of the 'Radiometric Bode's Law', an empirical relation between the solar wind energy input and radio power output of a variety of bodies in the solar system, some of which (e.g. Jupiter) are known to be dominated instead by internal processes such as planetary rotation. In this presentation we calculate the expected radio luminosity generated by a Dungey cycle-like stellar wind interaction with a hot Jupiter's magnetosphere. Specifically, we adapt the Milan (2013) model of the terrestrial twin-vortical ionospheric plasma flow and resulting field-aligned currents to the case of hot Jupiters, and we compute the total <span class="hlt">auroral</span> and radio luminosities for various parameters and compare with previous empirical estimates.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5095249','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5095249"><span id="translatedtitle"><span class="hlt">Auroral</span> and sub-<span class="hlt">auroral</span> interaction at the F-region ionosphere. Final report, 1 June 1987-30 June 1989</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Aarons, J.; Mendillo, M.</p> <p>1989-08-31</p> <p>Deterioration of satellite signals and fading on HF are results of the appearance of intense irregularities of the order of meters to several hundred meters in the F layer. At <span class="hlt">auroral</span> and sub-<span class="hlt">auroral</span> latitudes, the irregularities become intense and create serious problems. The interaction of the ionosphere during magnetic storms has been studied at <span class="hlt">auroral</span> and subauroral latitudes. Results include a model which shows the expansion during the injection phase of the magnetic storm and the effect of storm effects of the stored-up energy in the ring current during the recovery phase. In comparing observations with incoherent scatter data from Millstone Hill the total convection velocity appears to be the dominating parameter in the injection-phase creation of irregularities. This work will move to studying the global effects of individual storms since the storms can inhibit irregularities at the equator while creating them at <span class="hlt">auroral</span> and sub-<span class="hlt">auroral</span> latitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title50-vol12/pdf/CFR-2013-title50-vol12-sec600-745.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title50-vol12/pdf/CFR-2013-title50-vol12-sec600-745.pdf"><span id="translatedtitle">50 CFR 600.745 - Scientific <span class="hlt">research</span> <span class="hlt">activity</span>, exempted fishing, and exempted educational <span class="hlt">activity</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-10-01</p> <p>... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Scientific <span class="hlt">research</span> <span class="hlt">activity</span>, exempted...-STEVENS ACT PROVISIONS General Provisions for Domestic Fisheries § 600.745 Scientific <span class="hlt">research</span> <span class="hlt">activity</span>, exempted fishing, and exempted educational <span class="hlt">activity</span>. (a) Scientific <span class="hlt">research</span> <span class="hlt">activity</span>. Nothing in this...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title50-vol12/pdf/CFR-2012-title50-vol12-sec600-745.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title50-vol12/pdf/CFR-2012-title50-vol12-sec600-745.pdf"><span id="translatedtitle">50 CFR 600.745 - Scientific <span class="hlt">research</span> <span class="hlt">activity</span>, exempted fishing, and exempted educational <span class="hlt">activity</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-10-01</p> <p>... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Scientific <span class="hlt">research</span> <span class="hlt">activity</span>, exempted...-STEVENS ACT PROVISIONS General Provisions for Domestic Fisheries § 600.745 Scientific <span class="hlt">research</span> <span class="hlt">activity</span>, exempted fishing, and exempted educational <span class="hlt">activity</span>. (a) Scientific <span class="hlt">research</span> <span class="hlt">activity</span>. Nothing in this...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title50-vol12/pdf/CFR-2014-title50-vol12-sec600-745.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title50-vol12/pdf/CFR-2014-title50-vol12-sec600-745.pdf"><span id="translatedtitle">50 CFR 600.745 - Scientific <span class="hlt">research</span> <span class="hlt">activity</span>, exempted fishing, and exempted educational <span class="hlt">activity</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-10-01</p> <p>... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Scientific <span class="hlt">research</span> <span class="hlt">activity</span>, exempted...-STEVENS ACT PROVISIONS General Provisions for Domestic Fisheries § 600.745 Scientific <span class="hlt">research</span> <span class="hlt">activity</span>, exempted fishing, and exempted educational <span class="hlt">activity</span>. (a) Scientific <span class="hlt">research</span> <span class="hlt">activity</span>. Nothing in this...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1236775','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1236775"><span id="translatedtitle">On the formation and origin of substorm growth phase/onset <span class="hlt">auroral</span> arcs inferred from conjugate space-ground observations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Motoba, T.; Ohtani, S.; Anderson, B. J.; Korth, H.; Mitchell, D.; Lanzerotti, L. J.; Shiokawa, K.; Connors, M.; Kletzing, C. A.; Reeves, G. D.</p> <p>2015-10-27</p> <p>In this study, magnetotail processes and structures related to substorm growth phase/onset <span class="hlt">auroral</span> arcs remain poorly understood mostly due to the lack of adequate observations. In this study we make a comparison between ground-based optical measurements of the premidnight growth phase/onset arcs at subauroral latitudes and magnetically conjugate measurements made by the <span class="hlt">Active</span> Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) at ~780 km in altitude and by the Van Allen Probe B (RBSP-B) spacecraft crossing L values of ~5.0–5.6 in the premidnight inner tail region. The conjugate observations offer a unique opportunity to examine the detailed features of the arc location relative to large-scale Birkeland currents and of the magnetospheric counterpart. Our main findings include (1) at the early stage of the growth phase the quiet <span class="hlt">auroral</span> arc emerged ~4.3° equatorward of the boundary between the downward Region 2 (R2) and upward Region 1 (R1) currents; (2) shortly before the <span class="hlt">auroral</span> breakup (poleward <span class="hlt">auroral</span> expansion) the latitudinal separation between the arc and the R1/R2 demarcation narrowed to ~1.0°; (3) RBSP-B observed a magnetic field signature of a local upward field-aligned current (FAC) connecting the arc with the near-Earth tail when the spacecraft footprint was very close to the arc; and (4) the upward FAC signature was located on the tailward side of a local plasma pressure increase confined near L ~5.2–5.4. These findings strongly suggest that the premidnight arc is connected to highly localized pressure gradients embedded in the near-tail R2 source region via the local upward FAC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860019853','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860019853"><span id="translatedtitle">Observations of vertical winds and the origin of thermospheric gravity waves launched by <span class="hlt">auroral</span> substorms and westward travelling surges</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rees, D.</p> <p>1986-01-01</p> <p>Several sequences of observations of strong vertical winds in the upper thermosphere are discussed, in conjunction with models of the generation of such winds. In the <span class="hlt">auroral</span> oval, the strongest upward winds are observed in or close to regions of intense <span class="hlt">auroral</span> precipitation and strong ionospheric currents. The strongest winds, of the order of 100 to 200 m/sec are usually upward, and are both localized and of relatively short duration (10 to 20 min). In regions adjacent to those displaying strong upward winds, and following periods of upward winds, downward winds of rather lower magnitude (40 to about 80 m/sec) may be observed. Strong and rapid changes of horizontal winds are correlated with these rapid vertical wind variations. Considered from a large scale viewpoint, this class of strongly time dependent winds propagate globally, and may be considered to be gravity waves launched from an <span class="hlt">auroral</span> source. During periods of very disturbed geomagnetic <span class="hlt">activity</span>, there may be regions within and close to the <span class="hlt">auroral</span> oval where systematic vertical winds of the order of 50 m/sec will occur for periods of several hours. Such persistent winds are part of a very strong large scale horizontal wind circulation set up in the polar regions during a major geomagnetic disturbance. This second class of strong horizontal and vertical winds corresponds more to a standing wave than to a gravity wave, and it is not as effective as the first class in generating large scale propagating gravity waves and correlated horizontal and vertical oscillations. A third class of significant (10 to 30 m/sec) vertical winds can be associated with systematic features of the average geomagnetic energy and momentum input to the polar thermosphere, and appear in statistical studies of the average vertical wind as a function of Universal Time at a given location.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.8707M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.8707M"><span id="translatedtitle">On the formation and origin of substorm growth phase/onset <span class="hlt">auroral</span> arcs inferred from conjugate space-ground observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Motoba, T.; Ohtani, S.; Anderson, B. J.; Korth, H.; Mitchell, D.; Lanzerotti, L. J.; Shiokawa, K.; Connors, M.; Kletzing, C. A.; Reeves, G. D.</p> <p>2015-10-01</p> <p>Magnetotail processes and structures related to substorm growth phase/onset <span class="hlt">auroral</span> arcs remain poorly understood mostly due to the lack of adequate observations. In this study we make a comparison between ground-based optical measurements of the premidnight growth phase/onset arcs at subauroral latitudes and magnetically conjugate measurements made by the <span class="hlt">Active</span> Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) at ~780 km in altitude and by the Van Allen Probe B (RBSP-B) spacecraft crossing L values of ~5.0-5.6 in the premidnight inner tail region. The conjugate observations offer a unique opportunity to examine the detailed features of the arc location relative to large-scale Birkeland currents and of the magnetospheric counterpart. Our main findings include (1) at the early stage of the growth phase the quiet <span class="hlt">auroral</span> arc emerged ~4.3° equatorward of the boundary between the downward Region 2 (R2) and upward Region 1 (R1) currents; (2) shortly before the <span class="hlt">auroral</span> breakup (poleward <span class="hlt">auroral</span> expansion) the latitudinal separation between the arc and the R1/R2 demarcation narrowed to ~1.0°; (3) RBSP-B observed a magnetic field signature of a local upward field-aligned current (FAC) connecting the arc with the near-Earth tail when the spacecraft footprint was very close to the arc; and (4) the upward FAC signature was located on the tailward side of a local plasma pressure increase confined near L ~5.2-5.4. These findings strongly suggest that the premidnight arc is connected to highly localized pressure gradients embedded in the near-tail R2 source region via the local upward FAC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1236775-formation-origin-substorm-growth-phase-onset-auroral-arcs-inferred-from-conjugate-space-ground-observations','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1236775-formation-origin-substorm-growth-phase-onset-auroral-arcs-inferred-from-conjugate-space-ground-observations"><span id="translatedtitle">On the formation and origin of substorm growth phase/onset <span class="hlt">auroral</span> arcs inferred from conjugate space-ground observations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Motoba, T.; Ohtani, S.; Anderson, B. J.; Korth, H.; Mitchell, D.; Lanzerotti, L. J.; Shiokawa, K.; Connors, M.; Kletzing, C. A.; Reeves, G. D.</p> <p>2015-10-27</p> <p>In this study, magnetotail processes and structures related to substorm growth phase/onset <span class="hlt">auroral</span> arcs remain poorly understood mostly due to the lack of adequate observations. In this study we make a comparison between ground-based optical measurements of the premidnight growth phase/onset arcs at subauroral latitudes and magnetically conjugate measurements made by the <span class="hlt">Active</span> Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) at ~780 km in altitude and by the Van Allen Probe B (RBSP-B) spacecraft crossing L values of ~5.0–5.6 in the premidnight inner tail region. The conjugate observations offer a unique opportunity to examine the detailed features of the arcmore » location relative to large-scale Birkeland currents and of the magnetospheric counterpart. Our main findings include (1) at the early stage of the growth phase the quiet <span class="hlt">auroral</span> arc emerged ~4.3° equatorward of the boundary between the downward Region 2 (R2) and upward Region 1 (R1) currents; (2) shortly before the <span class="hlt">auroral</span> breakup (poleward <span class="hlt">auroral</span> expansion) the latitudinal separation between the arc and the R1/R2 demarcation narrowed to ~1.0°; (3) RBSP-B observed a magnetic field signature of a local upward field-aligned current (FAC) connecting the arc with the near-Earth tail when the spacecraft footprint was very close to the arc; and (4) the upward FAC signature was located on the tailward side of a local plasma pressure increase confined near L ~5.2–5.4. These findings strongly suggest that the premidnight arc is connected to highly localized pressure gradients embedded in the near-tail R2 source region via the local upward FAC.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED541180.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED541180.pdf"><span id="translatedtitle">Increasing Physical <span class="hlt">Activity</span> through Recess. <span class="hlt">Research</span> Brief</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Beighle, Aaron</p> <p>2012-01-01</p> <p>Regular physical <span class="hlt">activity</span> promotes important health benefits, reduces risk for obesity and is linked with enhanced academic performance among students. The U.S. Surgeon General recommends that children engage in at least 60 minutes of moderate physical <span class="hlt">activity</span> most days of the week, yet fewer than half of children ages 6 to 11 meet that…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5592125','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5592125"><span id="translatedtitle">S-20 photocathode <span class="hlt">research</span> <span class="hlt">activity</span>. Part I</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gex, F.; Huen, T.; Kalibjian, R.</p> <p>1983-11-22</p> <p>The goal of this <span class="hlt">activity</span> has been to develop and implement S-20 photocathode processing techniques at Lawrence Livermore National Laboratory (LLNL) in order to study the physical properties of the photocathode films. The present work is the initial phase of a planned <span class="hlt">activity</span> in understanding cathode fabrication techniques and the optical/electrical characterization of these films.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980008121','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980008121"><span id="translatedtitle">Alaskan <span class="hlt">Auroral</span> All-Sky Images on the World Wide Web</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stenbaek-Nielsen, H. C.</p> <p>1997-01-01</p> <p>In response to a 1995 NASA SPDS announcement of support for preservation and distribution of important data sets online, the Geophysical Institute, University of Alaska Fairbanks, Alaska, proposed to provide World Wide Web access to the Poker Flat <span class="hlt">Auroral</span> All-sky Camera images in real time. The Poker <span class="hlt">auroral</span> all-sky camera is located in the Davis Science Operation Center at Poker Flat Rocket Range about 30 miles north-east of Fairbanks, Alaska, and is connected, through a microwave link, with the Geophysical Institute where we maintain the data base linked to the Web. To protect the low light-level all-sky TV camera from damage due to excessive light, we only operate during the winter season when the moon is down. The camera and data acquisition is now fully computer controlled. Digital images are transmitted each minute to the Web linked data base where the data are available in a number of different presentations: (1) Individual JPEG compressed images (1 minute resolution); (2) Time lapse MPEG movie of the stored images; and (3) A meridional plot of the entire night <span class="hlt">activity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/993013','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/993013"><span id="translatedtitle">What Can be Learned from the Absence of <span class="hlt">Auroral</span> X-Ray Emission from Saturn?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hui, Yawei; Cravens, Thomas E. E.; Ozak, Nataly; Schultz, David Robert</p> <p>2010-01-01</p> <p>To understand the origin and magnitude of the present upper limit observations of Saturn's <span class="hlt">auroral</span> X-ray emission, we use simple models based on the mechanism that leads to analogous emission at Jupiter, charge transfer between ion precipitation and atmospheric gas. Several putative sources and characteristics of the precipitation are considered, namely, (1) highly charged solar wind ions with additional acceleration and (2) ambient, thermal ion population originating, for example, from Saturn's satellites, and then accelerated to high energies. Estimates obtained for each of these sources show the need for acceleration, either to focus the highly charged solar wind ions into the atmosphere or to enable stripping of the initially low-charge state ambient ions to higher charges. The former yields a constraint on the existing accelerating potentials present at Saturn but can only account for about a tenth of the observed upper limit to the <span class="hlt">auroral</span> luminosity, while the latter requires extremely low limits on the area (i.e., less than 100 km{sup 2}) over which field-aligned potentials are <span class="hlt">active</span> and needed to produce the acceleration to generate the observational upper limit on the X-ray luminosity. We therefore narrow the range of possible ion sources, the accelerating potentials required that are consistent with the present understanding of the magnetosphere, and model upper limit of X-ray emission from ion precipitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988sprm.agarT....B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988sprm.agarT....B"><span id="translatedtitle">Ionospheric scintillations and in-situ measurements at an <span class="hlt">auroral</span> location in the European sector</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Basu, Santimay; Basu, Sunanda; MacKenzie, Eileen; Weimer, Dan</p> <p>1988-03-01</p> <p>The orbiting HiLat satellite launched by the Defense Nuclear Agency in 1983 offered an opportunity for studying the ionospheric scintillation parameters in relation to the in-situ measurements of ionization density, drift velocity, field-aligned current, and particle precipitation during the sunspot minimum period. The results of such a morphological study performed by the Air Force Geophysics Laboratory based on their observations at the <span class="hlt">auroral</span> oval station of Tromso, Norway are discussed. The dynamics of the spatial and temporal extent of this region are illustrated in the invariant latitude/magnetic local time grid. The geometrical enhancement of scintillations observed during the alignment of the propagation path with the local magnetic L-shell is shown to be the most consistent and conspicuous feature of scintillations in the nighttime <span class="hlt">auroral</span> oval. The steepening of phase spectral slope in this region is indicative of the presence of L-shell aligned sheet-like irregularities at long scale lengths. The seasonal variation of total electron content (TEC) determined from the differential Doppler measurements of HiLat transmissions is discussed in relation to in-situ density measurements at 830 km. The results are also utilized to illustrate the dependence of ionospheric structure parameters on short-term variability of solar <span class="hlt">activity</span> during the sunspot minimum period. Special effort is made to illustrate that the joint study of scintillation/TEC and in-situ parameters provides an insight into the nature of magnetospheric coupling with the high latitude ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720045715&hterms=CONDUCTIVITY+ELECTRIC&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DCONDUCTIVITY%2BELECTRIC','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720045715&hterms=CONDUCTIVITY+ELECTRIC&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DCONDUCTIVITY%2BELECTRIC"><span id="translatedtitle">Dayside <span class="hlt">auroral</span>-oval plasma density and conductivity enhancements due to magnetosheath electron precipitation.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kennel, C. F.; Rees, M. H.</p> <p>1972-01-01</p> <p>Demonstration that magnetosheath electrons precipitating into the dayside <span class="hlt">auroral</span> oval are a significant source of ionization and consequently will lead to electrical conductivity enhancements within the oval. By assuming that the electrons are maintained isotropic by strong pitch-angle diffusion as they precipitate into the ionosphere, the precipitation heat flux can be simply related to solar-wind energy density and consequently to the level of magnetic <span class="hlt">activity</span>. For quiet solar-wind conditions, the heat fluxes of 1 to 10 ergs/sq cm/sec expected and observed lead to height-integrated Pedersen conductivity enhancements of 4 to 15 mhos. During magnetic storms the conductivity enhancements could increase by a factor of 3 to 5. Since the precipitating electrons are soft, the Hall conductivity enhancements are smaller than the Pedersen conductivity enhancements. For typical electric fields the computed conductivity enhancements lead to field-aligned currents bounding the enhancements in order-of-magnitude agreement with observation. The topside ionosphere should also have a density enhancement over the <span class="hlt">auroral</span> oval on the dayside.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6494197','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6494197"><span id="translatedtitle">Ionospheric scintillations and in-situ measurements at an <span class="hlt">auroral</span> location in the European sector</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Basu, S.; Basu, S.; MacKenzie, E.; Weimer, D.</p> <p>1987-05-01</p> <p>The orbiting HiLat satellite offered a unique opportunity for studying the ionospheric scintillation parameters in relation to the in-situ measurements of ionization density, drift velocity, field-aligned current, and particle precipitation during the sunspot minimum period. This paper discusses the results of such a morphological study based on observations at the <span class="hlt">auroral</span>-oval station of Tromso, Norway. The dynamics of the spatial and temporal extent of this region are illustrated in the invariant latitude/magnetic local time grid. The geometrical enhancement of scintillations observed during the alignment of the propagation path with the local magnetic L-shell is shown to be the most consistent and conspicuous feature of scintillations in the nighttime <span class="hlt">auroral</span> oval. The steepening of phase spectral slope in this region is indicative of the presence of L-shell aligned sheet-like irregularities at long scale lengths. The seasonal variational of total electron content (TEC) determined from the differential Doppler measurements of HiLat transmissions is discussed in relation to the in-situ density measurements at 830 km. The results are also utilized to illustrate the dependence of ionospheric structure parameters on short-term variability of solar <span class="hlt">activity</span> during the sunspot minimum period. Special effort is made to illustrate that the joint study of scintillation/TEC and in-situ parameters provides an insight into the nature of magnetospheric coupling with the high-latitude ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5049141','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5049141"><span id="translatedtitle">Signatures of the high-altitude polar cusp and dayside <span class="hlt">auroral</span> regions as seen by the Viking electric field experiment</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marklund, G.T.; Blomberg, L.G.; Faelthammar, C.G. ); Erlandson, R.E.; Potemra, T.A. )</p> <p>1990-05-01</p> <p>Electric field and satellite potential observations along 42 Viking orbits in the high-altitude (2R{sub E}) polar cusp and dayside <span class="hlt">auroral</span> region have been examined. Within the cusp the plasma density usually reaches a maximum, and it is typically very homogeneous, in contrast to the irregular and lower density in the cleft and dayside <span class="hlt">auroral</span> regions. The maxima in the plasma density are sometimes anticorrelated with the magnetic field strength, indicating a diamagnetic effect. The entire cusp and dayside <span class="hlt">auroral</span> regions are characterized by irregular and burstlike electric fields, comprising field reversals on various scales (up to 3 min or 500 km), the larger scales, however, being rare in the cusp. Another common feature in these regions is the high correlation between mutually orthogonal components of the electric and magnetic fields, both for large-scale variations across spatial structures and for wave and pulsations in the ULF frequency range. The electric field signatures in the cusp (in the 1100-1300 MLT sector) are, however, characteristically different from the cleft and oval field signatures in that the electric field is usually less intense and less structured and not correlated with the substorm <span class="hlt">activity</span> level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol1/pdf/CFR-2011-title48-vol1-sec27-408.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol1/pdf/CFR-2011-title48-vol1-sec27-408.pdf"><span id="translatedtitle">48 CFR 27.408 - Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-10-01</p> <p>... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Cosponsored <span class="hlt">research</span> and....408 Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>. (a) In contracts involving cosponsored <span class="hlt">research</span>... objectives of the contract. Since the purpose of the cosponsored <span class="hlt">research</span> and development, the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AIPC..738...15Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AIPC..738...15Y"><span id="translatedtitle">An overview of TPV <span class="hlt">research</span> <span class="hlt">activities</span> in Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yugami, Hiroo; Yamaguchi, Masafumi</p> <p>2004-11-01</p> <p>The thermophotovoltaic (TPV) <span class="hlt">research</span> <span class="hlt">activity</span> in Japan has prospered from the second half of the 90s. In this paper, we will present an overview of TPV <span class="hlt">research</span> <span class="hlt">activities</span> in Japan. TPV technologies have been surveyed by <span class="hlt">research</span> committees in NEDO as a part of the <span class="hlt">research</span> <span class="hlt">activity</span> of the New Sunshine Project. The TPV is considered as a new application of non-conventional solar cells, and the situation of TPV technologies, especially TPV cells, in USA and EU is surveyed. Systematic investigative <span class="hlt">research</span> on TPV systems was performed by ENAA on FY1997 and 1998. In this investigative <span class="hlt">research</span> on potential market for a TPV power source in Japan has been focused on how TPV can contribute to energy conservation and environmental protection and harmony, compared with conventional engine or turbine generators and underdeveloped power generation technologies such as fuel cells or chemical batteries, etc. In addition to the investigative <span class="hlt">research</span>, the technical <span class="hlt">research</span> <span class="hlt">activities</span> are introduced in this paper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009Natur.460..491L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009Natur.460..491L"><span id="translatedtitle">Asymmetric <span class="hlt">auroral</span> intensities in the Earth's Northern and Southern hemispheres</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Laundal, K. M.; Østgaard, N.</p> <p>2009-07-01</p> <p>It is commonly assumed that the aurora borealis (Northern Hemisphere) and aurora australis (Southern Hemisphere) are mirror images of each other because the charged particles causing the aurora follow the magnetic field lines connecting the two hemispheres. The particles are believed to be evenly distributed between the two hemispheres, from the source region in the equatorial plane of the magnetosphere. Although it has been shown that similar <span class="hlt">auroral</span> features in the opposite hemispheres can be displaced tens of degree in longitude and that seasonal effects can cause differences in global intensity, the overall <span class="hlt">auroral</span> patterns were still similar. Here we report observations that clearly contradict the common assumption about symmetric aurora: intense spots are seen at dawn in the Northern summer Hemisphere, and at dusk in the Southern winter Hemisphere. The asymmetry is interpreted in terms of inter-hemispheric currents related to seasons, which have been predicted but hitherto had not been seen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1984JGR....89..236P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1984JGR....89..236P&link_type=ABSTRACT"><span id="translatedtitle">Electric field and plasma density measurements in the <span class="hlt">auroral</span> electrojet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pfaff, R. F.; Kelley, M. C.; Fejer, B. G.; Kudeki, E.; Carlson, C. W.; Pedersen, A.; Hausler, B.</p> <p>1984-01-01</p> <p>Extensive experimental and theoretical studies of <span class="hlt">auroral</span> and equatorial electrojet irregularities have been conducted for the last two decades. The present investigation is concerned with electric field and plasma density fluctuation measurements made on board of the Porcupine II sounding rocket and on a free-flyer ejected from the main spacecraft. The Porcupine II sounding rocket payload was launched at 1922:00 UT from Kiruna, Sweden, on March 20, 1977. The considered results show electrostatic turbulence in the unstable <span class="hlt">auroral</span> E region confined to a layer between 96 and 121 km. The similarities between the observations of two simultaneous payloads spaced a few kilometers apart indicate that on a large scale, the electrojet turbulence displays uniform characteristics.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19730051495&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dnike','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19730051495&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dnike"><span id="translatedtitle">An example of anticorrelation of <span class="hlt">auroral</span> particles and electric fields.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maynard, N. C.; Bahnsen, A.; Christophersen, P.; Lundin, R.; Egeland, A.</p> <p>1973-01-01</p> <p>The question of whether correlation or anticorrelation should occur is complex and depends on many factors, e.g., the internal impedance of the source; the Pedersen conductivity, which in turn is dependent on the incident energy of the precipitated particles; whether space charge can build up; and the magnitude of the incoming flux. Data are presented from a case in which an anticorrelation between <span class="hlt">auroral</span> particles and electric fields is especially striking. The data were obtained from a Nike Tomahawk launched from the Norwegian rocket range at Andoya. The experiments carried are described briefly. The data support the anticorrelation model as one mechanism that can affect the electric field strength in <span class="hlt">auroral</span> regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19740057195&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dnike','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19740057195&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dnike"><span id="translatedtitle">Field-aligned currents and the <span class="hlt">auroral</span> electrojet</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cahill, L. J.; Potter, W. E.; Kintner, P. M.; Arnoldy, R. L.; Choy, L. W.</p> <p>1974-01-01</p> <p>A Nike Tomahawk with fields and particles payload was launched on Nov. 18, 1970, over a strong westward electrojet current and <span class="hlt">auroral</span> forms moving rapidly to the east. Electron fluxes moving up and down the magnetic field lines were measured. Upward-moving electrons below 1-keV energy were dominant and were equivalent to a net downward electric current that fluctuated between .2 and .6 microamp/sq m during the flight above 130 km. As the rocket traversed this broad region of downward electric current over and to the north of the <span class="hlt">auroral</span> forms, the horizontal electric field slowly rotated from east to west. The magnetic measurements indicate that the westward electrojet was a horizontal sheet of current several hundred kilometers in north-south extent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSMSA13A..08Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSMSA13A..08Z"><span id="translatedtitle"><span class="hlt">Auroral</span> Undulations During Magnetic Storms: TIMED/GUVI Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Y.; Paxton, L. J.; Morrison, D.; Lui, T.; Kil, H.; Wolven, B.; Meng, C. I.</p> <p>2005-05-01</p> <p>Giant undulations on the equatorward edge of the diffuse aurora have been identified in TIMED/GUVI <span class="hlt">auroral</span> images in the far ultraviolet wavelengths. Some new features have been observed: (1) The GUVI 121.6nm <span class="hlt">auroral</span> images provide direct optical evidence that the undulations occur in the proton aurora, (2) Undulations are not limited to the dusk sector, they can occur in all local time sectors, (3) Both large ionospheric ion drift velocity (1000 m/s and above) and strong velocity shear (> 0.1 1/s) appear to be a necessary condition for the undulation to occur, (4) While almost all of the undulation events are observed during magnetic storms (Dst < -60 nT), one exceptional case shows undulation in the dayside associated with a positive Dst (30 nT), a large solar wind speed and a high solar wind dynamic pressure. The undulations can be explained by the K-H instability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870045524&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcalvert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870045524&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcalvert"><span id="translatedtitle">Hollowness of the observed <span class="hlt">auroral</span> kilometric radiation pattern</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Calvert, W.</p> <p>1987-01-01</p> <p>Presumably also generated by electron cyclotron emission, the earth's <span class="hlt">auroral</span> kilometric radiation would be expected to exhibit a hollow pattern in the direction of the source magnetic field, similar to that reported for the comparable emissions from Jupiter. Although previously overlooked, such hollowness is clearly present in the new pattern measurements of Green and Gallagher (1985) at 56 kHz, occupying source-centered latitudes of 30 to 45 deg and hence occurring exactly where it was predicted and previously observed. Being distributed in longitude and spanning the entire evening sector, presumably reflecting a similar longitudinal distribution of <span class="hlt">auroral</span> zone sources, this hollowness is attributed to sources beamed preferentially in the poleward magnetic meridian.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850055566&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcalvert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850055566&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcalvert"><span id="translatedtitle">DE-1 measurements of AKR wave directions. [<span class="hlt">auroral</span> kilometric radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Calvert, W.</p> <p>1985-01-01</p> <p>In addition to its wave rotation sense, the direction of <span class="hlt">auroral</span> kilometric radiation (AKR) can also be measured with the plasma wave instrument on Dynamics Explorer 1, from the relative phase of the signals received by its orthogonal electric dipole antennas. By this method, which differs in principle from the previous spin-null method for measuring wave directions, it has been found possible to pinpoint the AKR source by triangulation, using measurements from different points along the DE-1 orbit. The resulting apparent source, in one instance, seemed to occupy a well-defined <span class="hlt">auroral</span>-zone invariant magnetic latitude and showed the expected increase of altitude with decreasing frequency. An analysis of the method also confirmed the validity of the previous rotation sense measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860037055&hterms=auroral+region+electric+potential+structure&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dauroral%2Bregion%2Belectric%2Bpotential%2Bstructure','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860037055&hterms=auroral+region+electric+potential+structure&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dauroral%2Bregion%2Belectric%2Bpotential%2Bstructure"><span id="translatedtitle">A simple kinetic theory of <span class="hlt">auroral</span> arc scales</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chiu, Y. T.</p> <p>1986-01-01</p> <p>A kinetic theory of the origins of the <span class="hlt">auroral</span> arc scale spectrum is presented in this paper. The conceptual basis of the theory is current conservation in a turbulent plasma at the magnetospheric equatorial region in which a field-aligned current is generated and the local electrostatic potential structure is forced to adjust to the presence of the field-aligned current. This simple model uses an ad hoc Ohm's law relationship between the perpendicular current and the perpendicular electric field, but with a negative conductance in the generator region so that J(perpendicular) x E(perpendicular) is less than 0. An exact solution of a simple model of the concept yields a bistatic <span class="hlt">auroral</span> generator for which multiple-arc formation is predicted if the field-aligned current exceeds a critical value. The predicted scale spectrum is inversely proportional to the square root of the field-aligned current strength spectrum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890058253&hterms=southwest+iowa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsouthwest%2Biowa','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890058253&hterms=southwest+iowa&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsouthwest%2Biowa"><span id="translatedtitle">Simulations and observations of heating of <span class="hlt">auroral</span> ion beams</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Winglee, R. M.; Dusenbery, P. B.; Collin, H. L.; Lin, C. S.; Persoon, A. M.</p> <p>1989-01-01</p> <p>Two-dimensional three-velocity electrostatic particle simulations were used to determine the nonlinear evolution of the distributions of <span class="hlt">auroral</span> ion beams and thereby to determine quantitatively signatures in the ion distributions produced by the ion-ion instability for a variety of plasma conditions in the <span class="hlt">auroral</span> zone. The signatures determined from these simulations were compared with observations from DE 1, making it possible to characterize semiquantitatively the heating of the ionospheric ions, and to investigate the causes of variability seen in the observations of Reiff et al. (1988). A comparison of the simulation with observations showed features consistent with heating via the ion-ion instability including perpendicular heating in the supersonic regime and parallel heating in the subsonic regime, and a change in the heating between these regimes as the ratio of the H(+) beam speed to the local sound speed decreases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770026773','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770026773"><span id="translatedtitle">On the role of magnetic mirroring in the <span class="hlt">auroral</span> phenomena</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lennartsson, W.</p> <p>1976-01-01</p> <p>On the basis of field and particle observations, it is suggested that a bright <span class="hlt">auroral</span> display is a part of a magnetosphere-ionosphere current system which is fed by a charge-separation process in the outer magnetosphere (or the solar wind). The upward magnetic-field-aligned current is flowing out of the display, carried mainly by downflowing electrons from the hot-particle populations in the outer magnetosphere (the ambient cold electrons being depleted at high altitudes). As a result of the magnetic mirroring of these downflowing current carriers, a large potential drop is set up along the magnetic field, increasing both the number flux and the kinetic energy of precipitating electrons. It is found that this simple basic model, when combined with wave-particle interactions, may be able to explain a highly diversified selection of <span class="hlt">auroral</span> particle observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22410312','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22410312"><span id="translatedtitle"><span class="hlt">Auroral</span> electrostatic solitons and supersolitons in a magnetized nonthermal plasma</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rufai, O. R.</p> <p>2015-05-15</p> <p>Exploiting the spacecraft measurements in the <span class="hlt">auroral</span> region, finite amplitude nonlinear low frequency electrostatic solitons and supersolitons in a magnetized plasma consisting of cold ions fluid, Boltzmann protons, and nonthermal hot electrons are studied by applying a pseudo-potential technique. The localized solution of the nonlinear structures is obtained through the charge neutrality condition. Further numerical investigation shows the existence of supersoliton solutions at supersonic Mach numbers regime. The amplitude of ion-acoustic structures decreased with an increase in nonthermal electrons and ion density ratio. For the plasma parameters relevant to the <span class="hlt">auroral</span> zone of the Earth's magnetosphere, the electric field amplitude of supersolitons is found to be about 9 mV/m, which is in agreement with satellite observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987JHATD...8..303M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987JHATD...8..303M"><span id="translatedtitle">Preliminary observations from the <span class="hlt">Auroral</span> and Ionospheric Remote Sensing imager</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meng, Ching I.; Huffman, Robert E.</p> <p>1987-09-01</p> <p>The scientific objectives and the instrumentation of the Polar BEAR's <span class="hlt">Auroral</span> and Ionospheric Remote Sensing (AIRS) experiment are described together with the techniques employed for global imaging and the results of preliminary observations. The AIRS four-color imager covers selected wavelengths in the visible/near UV and vacuum UV (VUV) ranges. The AIRS experiment also has advantages of narrow 3.0-nm VUV bandpath imaging, not possible with the use of interference filters, and of three alternative modes of operation (imaging, spectrometer, or photometer), possible by controlling the scan mirror and the spectrometer gridding motor. Because of the satellite's high altitude (about 1000 km), most of the <span class="hlt">auroral</span> oval can be imaged.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43..988B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43..988B"><span id="translatedtitle">Weakening of Jupiter's main <span class="hlt">auroral</span> emission during January 2014</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Badman, S. V.; Bonfond, B.; Fujimoto, M.; Gray, R. L.; Kasaba, Y.; Kasahara, S.; Kimura, T.; Melin, H.; Nichols, J. D.; Steffl, A. J.; Tao, C.; Tsuchiya, F.; Yamazaki, A.; Yoneda, M.; Yoshikawa, I.; Yoshioka, K.</p> <p>2016-02-01</p> <p>In January 2014 Jupiter's FUV main <span class="hlt">auroral</span> oval decreased its emitted power by 70% and shifted equatorward by ˜1°. Intense, low-latitude features were also detected. The decrease in emitted power is attributed to a decrease in <span class="hlt">auroral</span> current density rather than electron energy. This could be caused by a decrease in the source electron density, an order of magnitude increase in the source electron thermal energy, or a combination of these. Both can be explained either by expansion of the magnetosphere or by an increase in the inward transport of hot plasma through the middle magnetosphere and its interchange with cold flux tubes moving outward. In the latter case the hot plasma could have increased the electron temperature in the source region and produced the intense, low-latitude features, while the increased cold plasma transport rate produced the shift of the main oval.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790057276&hterms=ISIS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DISIS','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790057276&hterms=ISIS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DISIS"><span id="translatedtitle">Isis 1 observations at the source of <span class="hlt">auroral</span> kilometric radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benson, R. F.; Calvert, W.</p> <p>1979-01-01</p> <p>Observations of <span class="hlt">auroral</span> kilometric radiation (AKR) were made by Isis 1 in the source region. The radiation is found to be generated in the extraordinary mode just above the local cut-off frequency and to emanate nearly perpendicular to the magnetic field. It occurs within local depletions of electron density, where the ratio of plasma frequency to cyclotron frequency is less than 0.2. The density depletion is restricted to altitudes above about 2000 km, and the upper AKR frequency limit corresponds to the extraordinary cut-off frequency at this altitude. AKR is observed from Isis 1 above the nighttime <span class="hlt">auroral</span> zone over a wider extent in longitude than in latitude with an intense source region observed most often near 2200 LMT and 70 deg invariant latitude. It is directly related to inverted V electron precipitation events with an electron-to-wave energy conversion efficiency of the order of 0.1 to 1%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030016695&hterms=Auroras&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DAuroras','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030016695&hterms=Auroras&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DAuroras"><span id="translatedtitle">Ionospheric Convection in the Postnoon <span class="hlt">Auroral</span> Oval: SuperDARN and Polar UVI Observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kozlovsky, A.; Koustov, A.; Lyatsky, W.; Kangas, J.; Parks, G.; Chua, D.</p> <p>2002-01-01</p> <p>Super Dual <span class="hlt">Auroral</span> Radar Network (SuperDARN) observations, ultraviolet imaging from the Polar satellite (UVI), and particle precipitation data from DMSP satellites have been used to investigate the electrodynamics of the postnoon <span class="hlt">auroral</span> oval in the Northern hemisphere. We show that: (1) For negative IMF By, the convection reversal (CR) was co-located with the maximum of <span class="hlt">auroral</span> luminosity, but during positive IMF By the convection reversal was poleward of the <span class="hlt">auroral</span> oval up to several degrees in latitude; (2) Postnoon <span class="hlt">auroral</span> oval was associated with a large-scale upward field-aligned current (FAC) of the order of 6x10(exp -7). A m(exp -2) in magnitude (the FAC was inferred from the SuperDARN and UVI data). For negative IMF By, maximum of the <span class="hlt">auroral</span> intensity coincides in latitude with the maximum of the upward field-aligned current. However, for positive IMF By. the maximum of the upward FAC was shifted to the poleward edge of the <span class="hlt">auroral</span> oval; (3) In response to the IMF By turning from positive to negative, the maximum of the <span class="hlt">auroral</span> luminosity did not change its position noticeably, but the position of the convection reversal changed considerably from 80-81 degs to about 76 degs MLAT, and the maximum of FAC moved from 77-78 degs to about 76 degs MLAT. Thus, after IMF By turns negative, both the FAC maximum and CR tend to coincide with the <span class="hlt">auroral</span> maximum; (4) The IMF Bz positive deflection was followed by a decrease in both field-aligned current intensity and <span class="hlt">auroral</span> luminosity. However, the decrease in the <span class="hlt">auroral</span> luminosity lags behind the FAC decrease by about 12 min. Firstly, these observations allow us to suggest that the IMF By-related electric field can penetrate into the closed magnetosphere and produce convection and FAC changes in the region of the postnoon <span class="hlt">auroral</span> oval. Secondly, we suggest that the interchange instability is a promising mechanism for the postnoon auroras.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1980ApJ...241..719C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980ApJ...241..719C"><span id="translatedtitle">Nebular and <span class="hlt">auroral</span> forbidden transitions of AR IV in some planetary nebulae</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Czyzak, S. J.; Sonneborn, G.; Aller, L. H.; Shectman, S. A.</p> <p>1980-10-01</p> <p>Measurements of <span class="hlt">auroral</span> and nebular type transitions in several planetary nebulae of high surface brightness show that currently available collisional cross sections and transition probabilities for 3p(3) configurations in Ar(3+) may be in error. The observed <span class="hlt">auroral</span>/nebular line ratio is always larger than the predicted value, and the disagreement is further aggravated if <span class="hlt">auroral</span> lines are weakened by telluric line absorption.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900000860','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900000860"><span id="translatedtitle">Boost-phase discrimination <span class="hlt">research</span> <span class="hlt">activities</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cooper, David M.; Deiwert, George S.</p> <p>1989-01-01</p> <p>Theoretical <span class="hlt">research</span> in two areas was performed. The aerothermodynamics <span class="hlt">research</span> focused on the hard-body and rocket plume flows. Analytical real gas models to describe finite rate chemistry were developed and incorporated into the three-dimensional flow codes. New numerical algorithms capable of treating multi-species reacting gas equations and treating flows with large gradients were also developed. The computational chemistry <span class="hlt">research</span> focused on the determination of spectral radiative intensity factors, transport properties and reaction rates. Ab initio solutions to the Schrodinger equation provided potential energy curves transition moments (radiative probabilities and strengths) and potential energy surfaces. These surfaces were then coupled with classical particle reactive trajectories to compute reaction cross-sections and rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7060643','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7060643"><span id="translatedtitle">Particle simulation of <span class="hlt">auroral</span> double layers. Doctoral thesis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Smith, B.L.</p> <p>1992-06-01</p> <p>Externally driven magnetic reconnection has been proposed as a possible mechanism for production of <span class="hlt">auroral</span> electrons during magnetic substorms. Fluid simulations of magnetic reconnection lead to strong plasma flows towards the increasing magnetic field of the earth. These plasma flows must generate large scale potential drops to preserve global charge neutrality. We have examined currentless injection of plasma along a dipole magnetic field into a bounded region using both analytic techniques and particle simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM51G4338J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM51G4338J"><span id="translatedtitle">Ionospheric Current Closure of the Pre-existing <span class="hlt">Auroral</span> Arc</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, F.; Kivelson, M.; Strangeway, R. J.; Khurana, K. K.; Walker, R. J.; Weygand, J. M.</p> <p>2014-12-01</p> <p>An <span class="hlt">auroral</span> substorm commences when a discrete <span class="hlt">auroral</span> arc brightens and subsequently expands poleward and azimuthally. The arc that brightens is usually the most equatorward of several <span class="hlt">auroral</span> arcs that remain quiescent for ~5 to ~60 minutes before the break-up commences. This arc is often referred to as the "pre-existing <span class="hlt">auroral</span> arc (PAA)" or the "growth-phase arc". Till now, the ionospheric electrodynamics of the PAA has been studied extensively by ground radar, rockets and low-altitude spacecraft, and it is well established that the field-aligned currents (FAC) associated with the PAA in the ionosphere are current sheets that are narrow in latitude and elongated in longitude. However, it remains a question whether the ionospheric currents that connect the FAC pair of the PAA are meridional or azimuthal. In this study, we have identified ~180 PAA events from FAST measurements in 1998 and 1999 and used the statistics to investigate the ionospheric current closure of the PAA. We calculate the height-integrated Pedersen currents from the electric fields measured by FAST using an empirical ionospheric conductance model and infer the FAC density from the divergence of the Pedersen currents. We find that in the vicinity of the PAA, the FAC density inferred from the divergence of perpendicular currents mimics the trend of the FAC density inferred from magnetic perturbations seen on FAST, and that the boundaries between the upward and the downward FAC sheets inferred from two different approaches lie very close together. Additionally, the latitudinal gradient of the azimuthal component of the magnetic perturbation is much larger than the azimuthal gradient of the meridional component of the magnetic perturbation in the vicinity of the PAA, indicating that the density of a meridional current is much larger than that of an azimuthal current. Our observational analysis strongly suggests that the perpendicular current that closes the FAC pair of the PAA is a north</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850055565&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcalvert','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850055565&hterms=calvert&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcalvert"><span id="translatedtitle"><span class="hlt">Auroral</span> kilometric radiation triggered by type II solar radio bursts</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Calvert, W.</p> <p>1985-01-01</p> <p>The previously-reported triggering of <span class="hlt">auroral</span> kilometric radiation (AKR) during type III solar radio bursts was attributed to the incoming radio waves rather than other aspects of the burst's causative solar flare. This conclusion has now been confirmed by ISEE-1 and ISEE-3 observations showing AKR which seems to have been triggered also by a subsequent type II solar radio burst, up to eleven hours after the flare.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JGRA..108.1094S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JGRA..108.1094S"><span id="translatedtitle">Io-related Jovian <span class="hlt">auroral</span> arcs: Modeling parallel electric fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Su, Yi-Jiun; Ergun, Robert E.; Bagenal, Fran; Delamere, Peter A.</p> <p>2003-02-01</p> <p>Recent observations of <span class="hlt">auroral</span> arcs on Jupiter suggest that electrons are being accelerated downstream from Io's magnetic footprint, creating detectable emissions. The downstream electron acceleration is investigated using one-dimensional spatial, two-dimensional velocity static Vlasov solutions under the constraint of quasi-neutrality and an applied potential drop. The code determines self-consistent charged particle distributions and potential structure along a magnetic field flux tube in the upward (with respect to Jupiter) current region of Io's wake. The boundaries of the flux tube are the Io torus on one end and Jupiter's ionosphere on the other. The results indicate that localized electric potential drops tend to form at 1.5-2.5 RJ Jovicentric distance. A sufficiently high secondary electron density causes an <span class="hlt">auroral</span> cavity to be produced similar to that on Earth. Interestingly, the model results suggest that the proton and the hot electron population in the Io torus control the electron current densities between the Io torus and Jupiter and thus may control the energy flux and the brightness of the aurora downstream from Io's magnetic footprint. The parallel electric fields also are expected to create an unstable horseshoe electron distribution inside the <span class="hlt">auroral</span> cavity, which may lead to the shell electron cyclotron maser instability. Results from our model suggest that in spite of the differing boundary conditions and the large centrifugal potentials at Jupiter, the <span class="hlt">auroral</span> cavity formation may be similar to that of the Earth and that parallel electric fields may be the source mechanism of Io-controlled decametric radio emissions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970022819','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970022819"><span id="translatedtitle">Plasma Heating and Flow in an <span class="hlt">Auroral</span> Arc</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moore, T. E.; Chandler, M. O.; Pollock, C. J.; Reasoner, D. L.; Arnoldy, R. L.; Austin, B.; Kintner, P. M.; Bonnell, J.</p> <p>1996-01-01</p> <p>We report direct observations of the three-dimensional velocity distribution of selected topside ionospheric ion species in an <span class="hlt">auroral</span> context between 500 and 550 km altitude. We find heating transverse to the local magnetic field in the core plasma, with significant heating of 0(+), He(+), and H(+), as well as tail heating events that occur independently of the core heating. The 0(+) velocity distribution departs from bi-Maxwellian, at one point exhibiting an apparent ring-like shape. However, these observations are shown to be aliased within the <span class="hlt">auroral</span> arc by temporal variations that arc not well-resolved by the core plasma instrument. The dc electric field measurements reveal superthermal plasma drifts that are consistent with passage of the payload through a series of vortex structures or a larger scale circularly polarized hydromagnetic wave structure within the <span class="hlt">auroral</span> arc. The dc electric field also shows that impulsive solitary structures, with a frequency spectrum in the ion cyclotron frequency range, occur in close correlation with the tail heating events. The drift and core heating observations lend support to the idea that core ion heating is driven at low altitudes by rapid convective motions imposed by the magnetosphere. Plasma wave emissions at ion frequencies and parallel heating of the low-energy electron plasma are observed in conjunction with this <span class="hlt">auroral</span> form; however, the conditions are much more complex than those typically invoked in previous theoretical treatments of superthermal frictional heating. The observed ion heating within the arc clearly exceeds that expected from frictional heating for the light ion species H(+) and He(+), and the core distributions also contain hot transverse tails, indicating an anomalous transverse heat source.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19810061762&hterms=energy+efficiency&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Denergy%2Befficiency','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19810061762&hterms=energy+efficiency&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Denergy%2Befficiency"><span id="translatedtitle">Saturation and energy-conversion efficiency of <span class="hlt">auroral</span> kilometric radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wu, C. S.; Tsai, S. T.; Xu, M. J.; Shen, J. W.</p> <p>1981-01-01</p> <p>A quasi-linear theory is used to study the saturation level of the <span class="hlt">auroral</span> kilometric radiation. The investigation is based on the assumption that the emission is due to a cyclotron maser instability as suggested by Wu and Lee and Lee et al. The thermodynamic bound on the radiation energy is also estimated separately. The energy-conversion efficiency of the radiation process is discussed. The results are consistent with observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720007677','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720007677"><span id="translatedtitle">The harang discontinuity in <span class="hlt">auroral</span> belt ionospheric currents</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Herpner, J. P.</p> <p>1971-01-01</p> <p>Observations are compared to the Harang discontinuity to illustrate the reality and form of the discontinuity near midnight. High latitude magnetic disturbances and <span class="hlt">auroral</span> displays were not found to be completely identical on any two days. The typical diurnal behavior during the night hours between 60 and 70 deg magnetic latitude was illustrated, using two patterns. Convection, time variablity, and current continuity of the Harang discontinuity are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991mit..reptS....A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991mit..reptS....A"><span id="translatedtitle"><span class="hlt">Activities</span> of the <span class="hlt">Research</span> Laboratory of Electronics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Allen, Jonathan; Kleppner, Daniel</p> <p>1991-08-01</p> <p>This progress report contains both a statement of <span class="hlt">research</span> objectives and a summary of <span class="hlt">research</span> efforts for <span class="hlt">research</span> projects listed. Partial contents include: (1) submicron structures technology and <span class="hlt">research</span>; (2) microstructural evolution in thin films of electronic materials; (3) focused ion beam fabrication; (4) chemical reaction dynamics at surfaces; (5) measurement of electron-phonon interactions through large-amplitude phonon excitation; (6) chemical beam epitaxy of compound semiconductors; (7) high-frequency InAlAs/InGaAs metal-insulator-doped semiconductor field-effect transistors for telecommunications; (8) novel superconducting tunneling structures; (9) optics and quantum electronics; (10) superconducting electronic devices; (11) synchrotron X ray studies of surface disordering; (12) semiconductor surface studies; (13) single electron transistors; (14) quantum optics and photonics; (15) plasma dynamics; (16) electromagnetic wave theory and applications; (17) radio astronomy; (18) digital signal processing; (19) speech processing; (20) custom integrated circuits; (21) speech communication; (22) sensory communications; (23) signal transmission in the auditory system; and (24) linguistics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=music+AND+tempo&pg=7&id=EJ600323','ERIC'); return false;" href="http://eric.ed.gov/?q=music+AND+tempo&pg=7&id=EJ600323"><span id="translatedtitle">Action <span class="hlt">Research</span>: Conducting <span class="hlt">Activities</span> for Third Graders.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>James, Lorinda</p> <p>1998-01-01</p> <p>Discusses the action <span class="hlt">research</span> conducted on whether the use of conducting patterns will not only help students understand meter, but also assist them in grasping certain expressive qualities of music. Finds that the posttest showed a 10 percent gain overall in the understanding of meter, tempo, dynamics, and style. (CMK)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016MNRAS.459.1159L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016MNRAS.459.1159L&link_type=ABSTRACT"><span id="translatedtitle">3D modelling of stellar <span class="hlt">auroral</span> radio emission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leto, P.; Trigilio, C.; Buemi, C. S.; Umana, G.; Ingallinera, A.; Cerrigone, L.</p> <p>2016-06-01</p> <p>The electron cyclotron maser is the coherent emission process that gives rise to the radio lighthouse effect observed in the hot magnetic chemically peculiar star CU Virginis. It has also been proposed to explain the highly circularly polarized radio pulses observed in some ultracool dwarfs with spectral type earlier than M7. Coherent events of this kind resemble <span class="hlt">auroral</span> radio emission from the magnetized planets of the Solar system. In this article, we present a three-dimensional model able to simulate the timing and profile of the pulses emitted by those stars characterized by a dipolar magnetic field by following the hypothesis of the laminar source model, used to explain the beaming of terrestrial <span class="hlt">auroral</span> kilometric radiation. This model proves to be a powerful tool with which to understand the <span class="hlt">auroral</span> radio emission phenomenon, allowing us to derive some general conclusions about the effects of the model's free parameters on the features of coherent pulses and to learn more about the detectability of such pulsed radio emission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.4591G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.4591G"><span id="translatedtitle">The large-scale current system during <span class="hlt">auroral</span> substorms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gjerloev, J. W.; Hoffman, R. A.</p> <p>2014-06-01</p> <p>We present an empirical model of the equivalent current system in the ionosphere during the peak of a classical bulge-type <span class="hlt">auroral</span> substorm. This model is derived from measurements made by ~110 ground magnetometer stations during 116 substorms. The data are temporally and spatially organized using global <span class="hlt">auroral</span> images obtained by the Polar Visible Imaging System Earth Camera. The empirical equivalent current system displays three key features: a poleward shift of the westward electrojet connecting the postmidnight and premidnight components; a polar cap swirl; and significantly different magnitudes of the postmidnight and premidnight westward electrojets. This leads us to propose a two-wedge current system linking the ionosphere to the magnetosphere. The bulge current wedge is located in the premidnight region just equatorward of the open-closed field line boundary while another three-dimensional current system is located in the postmidnight region well within the <span class="hlt">auroral</span> oval. We use Biot and Savart calculations and Tsyganenko mapping and show that this new model is a likely solution for the large-scale current system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5940166','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5940166"><span id="translatedtitle">The current-voltage relationship in <span class="hlt">auroral</span> current sheets</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weimer, D.R. ); Gurnett, D.A.; Goertz, C.K. ); Menietti, J.D.; Burch, J.L. ); Sugiura, M. )</p> <p>1987-01-01</p> <p>The current-voltage relation within narrow <span class="hlt">auroral</span> current sheets is examined through the use of high-resolution data from the high-altitude Dynamics Explorer 1 satellite. The north-south perpendicular electric field and the east-west magnetic field are shown for three cases in which there are large amplitude, oppositely directed paired electric fields which are confined to a region less than 20 km wide. The magnetic field variations are found to be proportional to the second integral of the high-altitude perpendicular electric field. It is shown that at the small-scale limit, this relationship between {Delta}B and E is consistent with a linear Ohm's law relationship between the current density and the parallel potential drop along the magnetic field line. This linear relationship had previously been verified for large-scale <span class="hlt">auroral</span> formations greater than 20 km wide at the ionosphere. The evidence shown here extends the knowledge down to the scale size of discrete <span class="hlt">auroral</span> arcs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015A%26C....11..138L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015A%26C....11..138L"><span id="translatedtitle">The <span class="hlt">Auroral</span> Planetary Imaging and Spectroscopy (APIS) service</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lamy, L.; Prangé, R.; Henry, F.; Le Sidaner, P.</p> <p>2015-06-01</p> <p>The <span class="hlt">Auroral</span> Planetary Imaging and Spectroscopy (APIS) service, accessible online, provides an open and interactive access to processed <span class="hlt">auroral</span> observations of the outer planets and their satellites. Such observations are of interest for a wide community at the interface between planetology, magnetospheric and heliospheric physics. APIS consists of (i) a high level database, built from planetary <span class="hlt">auroral</span> observations acquired by the Hubble Space Telescope (HST) since 1997 with its mostly used Far-Ultraviolet spectro-imagers, (ii) a dedicated search interface aimed at browsing efficiently this database through relevant conditional search criteria and (iii) the ability to interactively work with the data online through plotting tools developed by the Virtual Observatory (VO) community, such as Aladin and Specview. This service is VO compliant and can therefore also been queried by external search tools of the VO community. The diversity of available data and the capability to sort them out by relevant physical criteria shall in particular facilitate statistical studies, on long-term scales and/or multi-instrumental multi-spectral combined analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850014169','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850014169"><span id="translatedtitle">Direct measurements of severe spacecraft charging in <span class="hlt">auroral</span> ionosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burke, W. J.; Hardy, D. A.; Rich, F. J.; Rubin, A. G.; Tautz, M. F.; Saflekos, N. A.; Yeh, H. C.</p> <p>1985-01-01</p> <p>Questions are addressed concerning how large space structures in polar orbit will interact with <span class="hlt">auroral</span> environments. Because spacecraft charging at ionospheric attitudes does not seriously threaten the operation of today's relatively small polar satellites the subject of environment interactions has not received the widespread attention given to it at geostationary altitude. As a matter of economics it is desirable to apply as much as possible of what was learned about spacecraft interactions at geostationary orbit to low Earth orbits. The environment at <span class="hlt">auroral</span> latitudes in the ionosphere differs from that encountered at geostationary altitude in at least two major aspects. (1) There is a large reservoir of high-density, cold plasma which tends to mitigate charging effects by providing a large source of charged particles from which neutralizing currents maybe drawn. Significant wake effects behind large structures will introduce new problems with differential charging. (2) Between the magnetic equator and the ionosphere, <span class="hlt">auroral</span> electrons frequently undergo field-aligned accelerations of several kilovolts. In such environments, fluxes of energetic protons are usually below the levels of instrumentation sensitivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20168774','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20168774"><span id="translatedtitle">Instrument for the monochromatic observation of all sky <span class="hlt">auroral</span> images.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mende, S B; Eather, R H; Aamodt, E K</p> <p>1977-06-01</p> <p>To investigate the dynamics of auroras and faint upper atmospheric emissions, a new type of imaging instrument was developed. The instrument is a wide field of view, narrow-spectral-band imaging system using an intensified S.E.C. TV camera in a time exposure mode. Pictures were taken at very low light levels of a few photons per exposure per resolution element. These pictures are displayed in the form of a pseudocolor presentation in which the color represents spectral ratios of two of the observed <span class="hlt">auroral</span> spectral emission features. The spectral ratios play an important part in the interpretation of <span class="hlt">auroral</span> particle dynamics. A digital picture processing facility is also part of the system which enables the digital manppulation of the pictures at standard TV rates. As an example, hydrogen auroras can be displayed having been corrected for nonspectral background by subtracting a picture obtained by a suitable background filter. The instrumentation was calibrated in the laboratory and was used in several field xperiments. Elaborate exposure sequences were developed to extend the dynamic range and to cover the large range of <span class="hlt">auroral</span> brightnesses in a fairly linear manner. PMID:20168774</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015JGRA..120.8085M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015JGRA..120.8085M&link_type=ABSTRACT"><span id="translatedtitle">The night when the <span class="hlt">auroral</span> and equatorial ionospheres converged</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martinis, C.; Baumgardner, J.; Mendillo, M.; Wroten, J.; Coster, A.; Paxton, L.</p> <p>2015-09-01</p> <p>An all-sky imaging system at the McDonald Observatory (30.67°N, 104.02°W, 40° magnetic latitude) showed dramatic ionospheric effects during a moderate geomagnetic storm on 1 June 2013. The <span class="hlt">auroral</span> zone expanded, leading to the observation of a stable <span class="hlt">auroral</span> red (SAR) arc. Airglow depletions associated with equatorial spread F (ESF) were also seen for the first time at such high magnetic latitude. Total electron content measurements from a Global Positioning System (GPS) receiver exhibited ionospheric irregularities typically associated with ESF. We explore why this moderate geomagnetic disturbance leads to such dramatic ionospheric perturbations at midlatitudes. A corotating interaction region-like driver and a highly contracted plasmasphere caused the SAR arc to occur at L shell ~ 2.3. For ESF at L ~ 2.1, timing of the storm intensification, alignment of the sunset terminator with the central magnetic meridian, and sudden variations in the westward <span class="hlt">auroral</span> electrojet all combined to trigger equatorial irregularities that reached altitudes of ~ 7000 km. The SAR arc and ESF signatures at the ionospheric foot points of inner magnetosphere L shells (L ~ 2) represent a dramatic convergence of pole to equator/equator to pole coupling at midlatitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E.553C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E.553C"><span id="translatedtitle">Features of the processes of ion heating in polar boundary of the night <span class="hlt">auroral</span> oval</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chugunin, Dmitriy; Lutsenko, Volt; Romantsova, Tatiana; Mogilevsky, Mikhail; Moiseenko, Irina</p> <p></p> <p>Investigation of the processes of ion heating in polar boundary of the night <span class="hlt">auroral</span> oval measured by INTERBALL-2 (<span class="hlt">Auroral</span> probe) is presented. Measurements of particles and waves were made on altitude about 20000 км. Feature of the orbits was the satellite slid along <span class="hlt">auroral</span> oval and stay long time in the <span class="hlt">auroral</span> zone. It were cases chosen when the polar boundary moved and passed through satellite. Particular attention is given to ions heating at this border and to ion heating position in relation to polar boundary of particle precipitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012RScEd..42.1073C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012RScEd..42.1073C"><span id="translatedtitle">Describing Changes in Undergraduate Students' Preconceptions of <span class="hlt">Research</span> <span class="hlt">Activities</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cartrette, David P.; Melroe-Lehrman, Bethany M.</p> <p>2012-12-01</p> <p><span class="hlt">Research</span> has shown that students bring naïve scientific conceptions to learning situations which are often incongruous with accepted scientific explanations. These preconceptions are frequently determined to be misconceptions; consequentially instructors spend time to remedy these beliefs and bring students' understanding of scientific concepts to acceptable levels. It is reasonable to assume that students also maintain preconceptions about the processes of authentic scientific <span class="hlt">research</span> and its associated <span class="hlt">activities</span>. This study describes the most commonly held preconceptions of authentic <span class="hlt">research</span> <span class="hlt">activities</span> among students with little or no previous <span class="hlt">research</span> experience. Seventeen undergraduate science majors who participated in a ten week <span class="hlt">research</span> program discussed, at various times during the program, their preconceptions of <span class="hlt">research</span> and how these ideas changed as a result of direct participation in authentic <span class="hlt">research</span> <span class="hlt">activities</span>. The preconceptions included the belief that authentic <span class="hlt">research</span> is a solitary <span class="hlt">activity</span> which most closely resembles the type of <span class="hlt">activity</span> associated with laboratory courses in the undergraduate curriculum. Participants' views showed slight maturation over the <span class="hlt">research</span> program; they came to understand that authentic <span class="hlt">research</span> is a detail-oriented <span class="hlt">activity</span> which is rarely successfully completed alone. These findings and their implications for the teaching and <span class="hlt">research</span> communities are discussed in the article.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840022386','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840022386"><span id="translatedtitle"><span class="hlt">Research</span> <span class="hlt">activities</span> of the Geodynamics Branch</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kahn, W. D. (Editor); Cohen, S. C. (Editor)</p> <p>1984-01-01</p> <p>A broad spectrum of geoscience disciplines including space geodesy, geopotential field modeling, tectonophysics, and dynamic oceanography are discussed. The NASA programs, include the Geodynamics and Ocean Programs, the Crustal Dynamics Project, the proposed Ocean Topography Experiment (TOPEX), and the Geopotential <span class="hlt">Research</span> Mission (GRM). The papers are grouped into chapters on Crustal Movements, Global Earth Dynamics, Gravity Field Model Development, Sea Surface Topography, and Advanced Studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.4959G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.4959G"><span id="translatedtitle">Vlasov simulations of electron trapping on <span class="hlt">auroral</span> field lines</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gunell, H.; Mann, I.; De Keyser, J.; Andersson, L.</p> <p>2012-04-01</p> <p>In the <span class="hlt">auroral</span> zone, electric fields that are parallel to the earth's magnetic field are known to exist and to contribute to the acceleration of <span class="hlt">auroral</span> electrons. Transverse electric fields at high altitude result in parallel electric fields as a consequence of the closure of the field-aligned currents through the conducting ionosphere (L. R. Lyons, JGR, vol. 85, 1724, 1980). These parallel electric fields can be supported by the magnetic mirror field (Alfvén and Fälthammar, Cosmical Electrodynamics, 2nd ed., 1963). Stationary kinetic models have been used to study the current-voltage characteristics of the <span class="hlt">auroral</span> current circuit (Knight, Planet. and Space Sci., vol. 21, 741-750, 1973). Fluid and hybrid simulations have been used to model parallel electric fields and Alfvén waves, and to study the relationship between them (e.g., Vedin and Rönnmark, JGR, vol. 111, 12201, 2006). Ergun, et al. (GRL, vol. 27, 4053-4056, 2000) found stationary Vlasov solutions over regions extending several Earth radii, and Main, et al. (PRL, vol. 97, 185001, 2006) performed Vlasov simulations of the <span class="hlt">auroral</span> acceleration region. Observations have shown that field-aligned potential drops often are concentrated in electric double layers (e.g. Ergun, et al., Phys. Plasmas, vol. 9, 3685-3694, 2002). In the upward current region, 20-50% of the total potential drop has been identified as localised. How the rest of the potential is spread out as function of altitude is not yet known from observations. Gunell et al. (submitted to GRL, 2012) performed Vlasov simulations, using a model that is one-dimensional in configuration space and two-dimensional in velocity space, and found that about half of the potential drop is found in a thin double layer. The other half is in a region, which extends a few earth radii above it. The double layer itself is stationary, while there are oscillations in the longer low-field region. The current-voltage characteristic approximately follows the Knight</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120016631','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016631"><span id="translatedtitle">NASA Glenn <span class="hlt">Research</span> Center Battery <span class="hlt">Activities</span> Overview</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Manzo, Michelle A.</p> <p>2009-01-01</p> <p>This paper will provide an overview of the planned energy storage systems for the Orion Spacecraft and the Aries rockets that will be used in the return journey to the Moon and GRC's involvement in their development. Technology development goals and approaches to provide batteries and fuel cells for the Altair Lunar Lander, the new space suit under development for extravehicular <span class="hlt">activities</span> (EVA) on the Lunar surface, and the Lunar Surface Systems operations will also be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010110017&hterms=atmospheric+corrosion&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Datmospheric%2Bcorrosion','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010110017&hterms=atmospheric+corrosion&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Datmospheric%2Bcorrosion"><span id="translatedtitle">Corrosion <span class="hlt">Research</span> And Web Site <span class="hlt">Activities</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Heidersbach, Robert H.</p> <p>2001-01-01</p> <p>This report covers corrosion-related <span class="hlt">activities</span> at the NASA Kennedy Space Center during the summer of 2000. The NASA Kennedy Space Center's corrosion web site, corrosion.ksc.nasa.gov, was updated with new information based on feedback over the past two years. The methodology for a two-year atmospheric exposure testing program to study the effectiveness of commercial chemicals sold for rinsing aircraft and other equipment was developed and some preliminary laboratory chemical analyses are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030002492&hterms=atmospheric+corrosion&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Datmospheric%2Bcorrosion','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030002492&hterms=atmospheric+corrosion&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Datmospheric%2Bcorrosion"><span id="translatedtitle">Corrosion <span class="hlt">Research</span> and Web Site <span class="hlt">Activities</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Heidersbach, Robert H.</p> <p>2002-01-01</p> <p>This report covers corrosion-related <span class="hlt">activities</span> at the NASA Kennedy Space Center during the summer of 2000. The NASA Kennedy Space Center's corrosion web site, corrosion.ksc.nasa.gov, was updated with new information based on feedback over the past two years. The methodology for a two-year atmospheric exposure testing program to study the effectiveness of commercial chemicals sold for rinsing aircraft and other equipment was developed and some preliminary laboratory chemical analyses are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=35295&keyword=stretford&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=64068462&CFTOKEN=95363224','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=35295&keyword=stretford&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=64068462&CFTOKEN=95363224"><span id="translatedtitle">EPA (ENVIRONMENTAL PROTECTION AGENCY) OIL SHALE <span class="hlt">RESEARCH</span> <span class="hlt">ACTIVITIES</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The paper is an overview of EPA's oil shale <span class="hlt">research</span> <span class="hlt">activities</span>. In spite of substantial cutbacks in the program, several new projects should not only be of interest to developers and <span class="hlt">researchers</span> but also support future regulatory and permitting decisions by the Agency. New <span class="hlt">activ</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title48-vol1/pdf/CFR-2013-title48-vol1-sec27-408.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title48-vol1/pdf/CFR-2013-title48-vol1-sec27-408.pdf"><span id="translatedtitle">48 CFR 27.408 - Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-10-01</p> <p>... development <span class="hlt">activities</span>. 27.408 Section 27.408 Federal Acquisition Regulations System FEDERAL ACQUISITION....408 Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>. (a) In contracts involving cosponsored <span class="hlt">research</span> and development that require the contractor to make substantial contributions of funds or resources...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=279427','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=279427"><span id="translatedtitle">Partnerships for progress in <span class="hlt">active</span> living: from <span class="hlt">research</span> to action</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>The theme for the 2011 <span class="hlt">Active</span> Living <span class="hlt">Research</span> Annual Conference was "Partnerships for Progress in <span class="hlt">Active</span> Living: From <span class="hlt">Research</span> to Action." The rationale for this theme was simple: no person is an island. The theme recognizes that partnerships are essential to identify and implement solutions for co...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=primary+AND+sources+AND+research&pg=5&id=EJ1050170','ERIC'); return false;" href="http://eric.ed.gov/?q=primary+AND+sources+AND+research&pg=5&id=EJ1050170"><span id="translatedtitle">Methods to Measure Physical <span class="hlt">Activity</span> Behaviors in Health Education <span class="hlt">Research</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Fitzhugh, Eugene C.</p> <p>2015-01-01</p> <p>Regular physical <span class="hlt">activity</span> (PA) is an important concept to measure in health education <span class="hlt">research</span>. The health education <span class="hlt">researcher</span> might need to measure physical <span class="hlt">activity</span> because it is the primary measure of interest, or PA might be a confounding measure that needs to be controlled for in statistical analysis. The purpose of this commentary is to…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=activity+AND+theory&pg=4&id=EJ973909','ERIC'); return false;" href="http://eric.ed.gov/?q=activity+AND+theory&pg=4&id=EJ973909"><span id="translatedtitle">Narratives and <span class="hlt">Activity</span> Theory as Reflective Tools in Action <span class="hlt">Research</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Stuart, Kaz</p> <p>2012-01-01</p> <p>Narratives and <span class="hlt">activity</span> theory are useful as socially constructed data collection tools that allow a <span class="hlt">researcher</span> access to the social, cultural and historical meanings that <span class="hlt">research</span> participants place on events in their lives. This case study shows how these tools were used to promote reflection within a cultural-historical <span class="hlt">activity</span> theoretically…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title48-vol1/pdf/CFR-2010-title48-vol1-sec27-408.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title48-vol1/pdf/CFR-2010-title48-vol1-sec27-408.pdf"><span id="translatedtitle">48 CFR 27.408 - Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-10-01</p> <p>... development <span class="hlt">activities</span>. 27.408 Section 27.408 Federal Acquisition Regulations System FEDERAL ACQUISITION....408 Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>. (a) In contracts involving cosponsored <span class="hlt">research</span> and development that require the contractor to make substantial contributions of funds or resources...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title48-vol1/pdf/CFR-2012-title48-vol1-sec27-408.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title48-vol1/pdf/CFR-2012-title48-vol1-sec27-408.pdf"><span id="translatedtitle">48 CFR 27.408 - Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-10-01</p> <p>... development <span class="hlt">activities</span>. 27.408 Section 27.408 Federal Acquisition Regulations System FEDERAL ACQUISITION....408 Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>. (a) In contracts involving cosponsored <span class="hlt">research</span> and development that require the contractor to make substantial contributions of funds or resources...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title48-vol1/pdf/CFR-2014-title48-vol1-sec27-408.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title48-vol1/pdf/CFR-2014-title48-vol1-sec27-408.pdf"><span id="translatedtitle">48 CFR 27.408 - Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-10-01</p> <p>... development <span class="hlt">activities</span>. 27.408 Section 27.408 Federal Acquisition Regulations System FEDERAL ACQUISITION....408 Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>. (a) In contracts involving cosponsored <span class="hlt">research</span> and development that require the contractor to make substantial contributions of funds or resources...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5258751','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5258751"><span id="translatedtitle">Comparison between the polar cap index, PC and the <span class="hlt">auroral</span> electrojet indices AE, AL, and AU</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vennerstrom, S.; Friis-Christensen, E. ); Troshichev, O.A.; Andresen, V.G. )</p> <p>1991-01-01</p> <p>The newly introduced index PC for magnetic <span class="hlt">activity</span> in the polar cap has been examined to establish to which extent it can serve as an indicator of <span class="hlt">auroral</span> electrojet <span class="hlt">activity</span>. PC is derived from a single nearpole station, as a 15-min average index. The authors have derived it for two stations, one in the northern hemisphere (Thule) and one in the southern hemisphere (Vostok). The simplicity of the PC index enables us to make a large data base for statistical investigations. They have thus used 7 years of PC values for the two stations to analyze the relationship between PC and the <span class="hlt">auroral</span> zone indices AE, AU, and AL statistically. They find a very high correlation between PC and AE during winter and equinox, the linear correlation coefficient being {approximately} 0.8-0.9 for Thule and {approximately} 0.7-0.8 for Vostok. During summer the correlation is less because the PC index is then disturbed by polar cap currents controlled by the northward and east-west components of the interplanetary magnetic field. They therefore stress the importance of having PC available from both the northern and southern hemisphere. From event studies they find that PC is sensitive both to DP 2 type electrojet <span class="hlt">activity</span> and to substorm intensifications of the westward electrojet in the midnight or postmidnight sector but less sensitive to substorm intensifications of the westward electrojet in the midnight or post midnight sector. They conclude that PC can serve as a fast available indicator of DP 2 and DP 1 <span class="hlt">activity</span> in the polar regions, excluding intrusions of the westward electrojet in the premidnight sector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070008108','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070008108"><span id="translatedtitle">Human <span class="hlt">Research</span> Program Science Management: Overview of <span class="hlt">Research</span> and Development <span class="hlt">Activities</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Charles, John B.</p> <p>2007-01-01</p> <p>An overview of <span class="hlt">research</span> and development <span class="hlt">activities</span> of NASA's Human <span class="hlt">Research</span> Science Management Program is presented. The topics include: 1) Human <span class="hlt">Research</span> Program Goals; 2) Elements and Projects within HRP; 3) Development and Maintenance of Priorities; 4) Acquisition and Evaluation of <span class="hlt">Research</span> and Technology Proposals; and 5) Annual Reviews</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/976215','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/976215"><span id="translatedtitle">The Evolution of North-South Aligned <span class="hlt">Auroral</span> Forms into <span class="hlt">Auroral</span> Torch Structures : The Generation of Omega Bands and Ps6 Pulsations via Flow Bursts.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Henderson, M. G.; Kepko, L.; Spence, H. E.; Connors, M.; Sigwarth, J. B.; Frank, L. A.; Singer, H. J.; Yumoto, K.</p> <p>2002-01-01</p> <p>Although <span class="hlt">auroral</span> torch structures and omega bands have been observed and studied for decades, a satisfactory understanding of how they form has yet to be achieved. Using global <span class="hlt">auroral</span> imager data, we show conclusively that the equatorward moving north-south (NS) aligned <span class="hlt">auroral</span> forms that are ejected episodically from the poleward boundary can evolve directly into torch structures which contribute to a well-defined omega-band form. And that as a consequence, omega bands can be produced as a direct result of earthward-directed bursty bulk flows (BBFs).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.U22B..03Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.U22B..03Y"><span id="translatedtitle">The Earth's Interaction With the Sun Over the Millennia From Analyses of Historical Sunspot, <span class="hlt">Auroral</span> and Climate Records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yau, K.</p> <p>2001-12-01</p> <p>A prolonged decrease in the Sun's irradiance during the Maunder Minimum has been proposed as a cause of the Little Ice Age ({ca} 1600-1800). Eddy [{Science} {192}, 1976, 1189] made this suggestion after noting that very few sunspots were observed from 1645 to 1715, indicative of a weakened Sun. Pre-telescopic Oriental sunspot records go back over 2200 years. Periods when no sunspots were seen have been documented by, {eg}, Clark [{Astron} {7}, 2/1979, 50]. Abundances of C 14 in tree rings and Be10 in ice cores are also good indicators of past solar <span class="hlt">activity</span>. These isotopes are produced by cosmic rays high in the atmosphere. When the Sun is less <span class="hlt">active</span> more of them are made and deposited at ground level. There is thus a strong {negative} correlation between their abundances and sunspot counts. Minima of solar <span class="hlt">activity</span> in tree rings and a south polar ice core have been collated by, {eg}, Bard [{Earth Planet Sci Lett} {150} 1997, 453]; and show striking correspondence with periods when no sunspots were seen, centered at {ca} 900, 1050, 1500, 1700. Pang and Yau [{Eos} {79}, #45, 1998, F149] investigated the Medieval Minimum at 700, using in addition the frequency of <span class="hlt">auroral</span> sighting7s, a good indicator of solar <span class="hlt">activity</span> too [Yau, PhD thesis, 1988]; and found that the progression of minima in solar <span class="hlt">activity</span> goes back to 700. <span class="hlt">Auroral</span> frequency, C 14 and Be 10 concentrations are also affected by variations in the geomagnetic field. Deposition changes can also influence C 14 and Be 10 abundances. Sunspot counts are thus the only true indicator of solar <span class="hlt">activity</span>. The Sun's bolometric variations (-0.3% for the Maunder Minimum) can contribute to climatic changes (\\0.5° C for the Little Ice Age)[{eg}, Lean, {GRL} {22}, 1995, 3195]. For times with no thermometer data, temperature can be estimated from, {eg}, Oxygen 18 isotopic abundance in ice cores, which in turn depends on the temperature of the ocean water it evaporated from. We have linked the Medieval Minimum to the cold</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009JSDD....3..270K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009JSDD....3..270K&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Research</span> on an <span class="hlt">Active</span> Seat Belt System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kawashima, Takeshi</p> <p></p> <p>In a car crash, permanent injury can be avoided if deformation of an occupant's rib cage is maintained within the allowable value. In order to realize this condition, the occupant's seat belt tension must be instantaneously adjusted by a feedback control system. In this study, a seat belt tension control system based on the <span class="hlt">active</span> shock control system is proposed. The semi-<span class="hlt">active</span> control law used is derived from the sliding mode control method. One advantage of this proposed system is that it does not require a large power actuator because the seat belt tension is controlled by a brake mechanism. The effectiveness is confirmed by numerical simulation using general parameters of a human thorax and a passenger car in a collision scenario with a wall at a velocity of 100 km/h. The feasibility is then confirmed with a control experiment using a scale model of about 1/10 scale. The relative displacement of the thorax model approaches the allowable value smoothly along the control reference and settles near this value. Thus, the proposed seat belt tension control system design is established.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title48-vol5/pdf/CFR-2010-title48-vol5-sec927-408.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title48-vol5/pdf/CFR-2010-title48-vol5-sec927-408.pdf"><span id="translatedtitle">48 CFR 927.408 - Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-10-01</p> <p>... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Cosponsored <span class="hlt">research</span> and... Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>. Because of the Department of Energy's statutory duties to disseminate data first produced under its contracts for <span class="hlt">research</span>, development, and demonstration,...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=ADN&pg=5&id=EJ325490','ERIC'); return false;" href="http://eric.ed.gov/?q=ADN&pg=5&id=EJ325490"><span id="translatedtitle">A Typology of Nursing <span class="hlt">Research</span> <span class="hlt">Activities</span> According to Educational Preparation.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Fawcett, Jacqueline</p> <p>1985-01-01</p> <p>A typology of <span class="hlt">research</span> <span class="hlt">activities</span> (generation of basic, applied, and clinical <span class="hlt">research</span>; dissemination of findings; and use of findings) considered appropriate to nurses with different levels of educational preparation (ADN, BSN, MSN, DNSc/EdD, and PhD) is presented to assist potential <span class="hlt">researchers</span> and nurse educators in undertaking realistic and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol5/pdf/CFR-2011-title48-vol5-sec927-408.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol5/pdf/CFR-2011-title48-vol5-sec927-408.pdf"><span id="translatedtitle">48 CFR 927.408 - Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-10-01</p> <p>... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Cosponsored <span class="hlt">research</span> and... Cosponsored <span class="hlt">research</span> and development <span class="hlt">activities</span>. Because of the Department of Energy's statutory duties to disseminate data first produced under its contracts for <span class="hlt">research</span>, development, and demonstration,...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20123824','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20123824"><span id="translatedtitle">Rational protection of subjects in <span class="hlt">research</span> and quality improvement <span class="hlt">activities</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Goldman, Beth; Dixon, Lisa B; Adler, David A; Berlant, Jeffrey; Dulit, Rebecca A; Hackman, Ann; Oslin, David W; Siris, Samuel G; Valenstein, Marcia</p> <p>2010-02-01</p> <p>This Open Forum illuminates shortcomings with the basis for determining degree of oversight of health services <span class="hlt">research</span> and quality improvement <span class="hlt">activities</span>. Using a federally regulated definition of <span class="hlt">research</span> rather than a direct appraisal of risk to patients can misallocate effort from <span class="hlt">activities</span> with higher risk for patients to those with lower risk. The case of the Johns Hopkins multicenter study of central line safety checklists in intensive care units is cited. Definitions of <span class="hlt">research</span> promulgated by the Office of Human <span class="hlt">Research</span> Protection are reviewed, and an alternative model based on patient risk is proposed. Suggestions for how quality improvement work fits into the larger paradigm of <span class="hlt">research</span> are made. PMID:20123824</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040006337&hterms=sor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsor','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040006337&hterms=sor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsor"><span id="translatedtitle">[<span class="hlt">Activities</span> of Bay Area <span class="hlt">Research</span> Corporation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2003-01-01</p> <p>During the final year of this effort the HALFSHEL code was converted to work on a fast single processor workstation from it s parallel configuration. This was done because NASA Ames NAS facility stopped supporting space science and we no longer had access to parallel computer time. The single processor version of HALFSHEL was upgraded to address low density cells by using a a 3-D SOR solver to solve the equation Delta central dot E = 0. We then upgraded the ionospheric load packages to provide a multiple species load of the ionosphere out to 1.4 Rm. With these new tools we began to perform a series of simulations to address the major topic of this <span class="hlt">research</span> effort; determining the loss rate of O(sup +) and O2(sup +) from Mars. The simulations used the nominal Parker spiral field and in one case used a field perpendicular to the solar wind flow. The simulations were performed for three different solar EUV fluxes consistent with the different solar evolutionary states believed to exist before today. The 1 EUV case is the nominal flux of today. The 3 EUV flux is called Epoch 2 and has three times the flux of todays. The 6 EUV case is Epoch 3 and has 6 times the EUV flux of today.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=correlations&pg=2&id=EJ1066498','ERIC'); return false;" href="http://eric.ed.gov/?q=correlations&pg=2&id=EJ1066498"><span id="translatedtitle">Relationships between Interlibrary Loan and <span class="hlt">Research</span> <span class="hlt">Activity</span> in Canada</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Duy, Joanna; Larivière, Vincent</p> <p>2014-01-01</p> <p>Interlibrary Loan borrowing rates in academic libraries are influenced by an array of factors. This article explores the relationship between interlibrary loan borrowing <span class="hlt">activity</span> and <span class="hlt">research</span> <span class="hlt">activity</span> at 42 Canadian academic institutions. A significant positive correlation was found between interlibrary loan borrowing <span class="hlt">activity</span> and measures of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25414921','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25414921"><span id="translatedtitle">Zoo visitors' understanding of terms denoting <span class="hlt">research</span> <span class="hlt">activity</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carson, Lloyd</p> <p>2014-07-01</p> <p>Zoos have increasingly sought to justify their existence by reference to a scientific role particularly in the domains of animal welfare and conservation. Given recent initiatives by the UK government to foster public engagement with science, it is timely to investigate public attitudes towards primary <span class="hlt">research</span> <span class="hlt">activity</span> by zoos. This study reports the views of 83 visitors to Edinburgh Zoo. Within certain items in a structured interview noun terms denoting <span class="hlt">research</span> <span class="hlt">activity</span> were manipulated ("<span class="hlt">research</span>" versus "studies") as was their qualification (adjective "scientific" present or absent before the noun term). "<span class="hlt">Research</span>" was associated with a restricted and negative perception of investigatory <span class="hlt">activity</span>. This effect was intensified when the noun term was preceded by "scientific". It is concluded that there is a continuing need to challenge public perceptions, particularly of the phrase "scientific <span class="hlt">research</span>"; that in the meantime zoos should perhaps exercise caution when using it in relation to their <span class="hlt">activities</span>. PMID:25414921</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23540204','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23540204"><span id="translatedtitle"><span class="hlt">Research</span> on substances with <span class="hlt">activity</span> against orthopoxviruses.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kołodziej, Marcin; Joniec, Justyna; Bartoszcze, Michał; Gryko, Romuald; Kocik, Janusz; Knap, Józef</p> <p>2013-01-01</p> <p>Although smallpox was eradicated over 30 years ago, the disease remains a major threat. High mortality, high infectivity and low resistance of the contemporary population make the smallpox virus very attractive to terrorists. The possible presence of illegal stocks of the virus or risk of deliberate genetic modifications cause serious concerns among experts. Hence, it is reasonable to seek effective drugs that could be used in case of smallpox outbreak. This paper reviews studies on compounds with proven in vitro or in vivo antipoxviruses potential, which show various mechanisms of action. Nucleoside analogues, such as cidofovir, can inhibit virus replication. Cidofovir derivatives are developed to improve the bioavailability of the drug. Among the nucleoside analogues under current investigation are: ANO (adenozine N1-oxide) and its derivatives, N-methanocarbothymidine [(N)-MCT], or derivatitives of aciklovir, peninclovir and brivudin. Recently, ST-246 - which effectively inhibits infection by limiting release of progeny virions - has become an object of attention. It has been also been demonstrated that compounds such as: nigericin, aptamers and peptides may have antiviral potential. An interesting strategy to fight infections was presented in experiments aimed at defining the role of individual genes (E3L, K3L or C6L) in the pathogenesis, and looking for their potential blockers. Additionally, among substances considered to be effective in the treatment of smallpox cases, there are factors that can block viral inhibitors of the human complement system, epidermal growth factor inhibitors or immunomodulators. Further studies on compounds with <span class="hlt">activity</span> against poxviruses are necessary in order to broaden the pool of available means that could be used in the case of a new outbreak of smallpox. PMID:23540204</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19740048173&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dnike','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19740048173&hterms=nike&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dnike"><span id="translatedtitle">Field aligned currents and the <span class="hlt">auroral</span> spectrum below 1 keV</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Arnoldy, R. L.</p> <p>1973-01-01</p> <p>Measurements during <span class="hlt">auroral</span> events were conducted with the aid of detectors flown aboard three Nike-Tomahawk rocket flights. The detectors used to measure the <span class="hlt">auroral</span> spectrum below 1 keV consisted of electrostatic analyzers positioned in the rocket to measure particles moving up and down the magnetic field lines. The analyzers measured electrons and protons simultaneously during a given sweep.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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